diff --git a/src/main.ts b/src/main.ts
index 2f747aa..990aa85 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -26,12 +26,12 @@ function gameLoop (state: GameState, renderer: IRenderer): void {
   const state = config.generateState();
 
   // re-run main loop immediately on user clicks
-  state.onResourceClick = () => {
+  state.onResourceClick.push(() => {
     if (globalTimeout !== null) {
       clearTimeout(globalTimeout);
       gameLoop(state, renderer);
     }
-  }
+  });
 
   if (document.readyState !== 'loading') gameLoop(state, renderer);
   else document.addEventListener('DOMContentLoaded', () => gameLoop(state, renderer));
diff --git a/src/model/GameConfig.ts b/src/model/GameConfig.ts
index 75e20ef..25791c9 100644
--- a/src/model/GameConfig.ts
+++ b/src/model/GameConfig.ts
@@ -1,7 +1,7 @@
 /// <reference path="./GameState.ts" />
 /// <reference path="./resource/Money.ts" />
-/// <reference path="./resource/PlayerOrganization.ts" />
 /// <reference path="./resource/Religion.ts" />
+/// <reference path="./resource/SavingsBonds.ts" />
 
 class GameConfig {
   public worldPopulation: number = 790000000;
@@ -20,7 +20,8 @@ class GameConfig {
     const state = new GameState();
 
     // create player organization
-    state.addResource('plorg', new PlayerOrganization());
+    state.addResource('plorg', new Religion(
+      'Player', 'In you they trust.', 0));
 
     // create world religions
     state.addResource('xtian', new Religion(
@@ -55,8 +56,9 @@ class GameConfig {
       'Non-Religious', 'Atheists and agnostics.',
       this.relNoneShare * this.worldPopulation));
 
-    // add crafting resources
+    // add purchasable resources
     state.addResource('money', new Money(0, 1000));
+    state.addResource('bonds', new SavingsBonds(0));
 
     return state;
   }
diff --git a/src/model/GameState.ts b/src/model/GameState.ts
index af3ec18..daccdb6 100644
--- a/src/model/GameState.ts
+++ b/src/model/GameState.ts
@@ -4,7 +4,7 @@ class GameState {
   private _resources: Record<string, IResource> = { };
   private _resourceKeys: string[] = [];
 
-  public onResourceClick: () => void = null;
+  public onResourceClick: (() => void)[] = [];
 
   public addResource (key: string, resource: IResource): void {
     this._resourceKeys.push(key);
@@ -30,22 +30,28 @@ class GameState {
   public performClick (resourceKey: string): void {
     if (this._resources[resourceKey].clickAction !== null) {
       this._resources[resourceKey].clickAction(this);
-      if (this.onResourceClick !== null) {
-        this.onResourceClick();
+      for (const callback of this.onResourceClick) {
+        callback();
       }
     }
   }
 
   public deductCost (cost: { [rkey: string]: number }): boolean {
     if (cost === null || Object.keys(cost) === null) return true;
-    for (const rkey of Object.keys(cost)) {
-      if (this._resources[rkey].value < cost[rkey]) {
-        return false;
-      }
-    }
+    if (!this.isPurchasable(cost)) return false;
     for (const rkey of Object.keys(cost)) {
       this._resources[rkey].value -= cost[rkey];
     }
     return true;
   }
+
+  public isPurchasable (cost: { [rkey: string]: number }): boolean {
+    if (cost === null || Object.keys(cost) === null) return true;
+    for (const rkey of Object.keys(cost)) {
+      if (this._resources[rkey].value < cost[rkey]) {
+        return false;
+      }
+    }
+    return true;
+  }
 }
diff --git a/src/model/resource/IResource.ts b/src/model/resource/IResource.ts
index 2eb8937..7ded881 100644
--- a/src/model/resource/IResource.ts
+++ b/src/model/resource/IResource.ts
@@ -11,7 +11,9 @@ interface IResource {
   resourceType: ResourceType;
   value: number;
   max?: number;
-  unlocked: boolean;
+  cost: { [key: string]: number };
+
+  isUnlocked: (state: GameState) => boolean;
 
   clickText: string;
   clickDescription: string;
diff --git a/src/model/resource/Money.ts b/src/model/resource/Money.ts
index 9545106..043c244 100644
--- a/src/model/resource/Money.ts
+++ b/src/model/resource/Money.ts
@@ -5,9 +5,12 @@ class Money extends Purchasable {
     public value: number,
     public max: number
   ) {
-    super('Money', 'Used to purchase goods and services.', null);
+    super('Money', 'Used to purchase goods and services.');
     this.clickText = 'Beg';
     this.clickDescription = 'Alms for the poor.';
-    this.unlocked = true;
+  }
+
+  public isUnlocked (state: GameState): boolean {
+    return true;
   }
 }
diff --git a/src/model/resource/PlayerOrganization.ts b/src/model/resource/PlayerOrganization.ts
deleted file mode 100644
index 8f6c628..0000000
--- a/src/model/resource/PlayerOrganization.ts
+++ /dev/null
@@ -1,18 +0,0 @@
-/// <reference path="./IResource.ts" />
-
-class PlayerOrganization implements IResource {
-  public readonly name = 'Player';
-  public readonly description = 'In you they trust.';
-  public readonly resourceType = ResourceType.Religion;
-  public readonly max?: number = null;
-  public readonly unlocked = true;
-
-  public readonly clickText: string = null;
-  public readonly clickDescription: string = null;
-  public readonly clickAction: () => void = null;
-
-  public readonly advanceAction: (time: number) => void = null;
-
-  public value = 0;
-
-}
diff --git a/src/model/resource/Purchasable.ts b/src/model/resource/Purchasable.ts
index 8e1d1b8..e4bd662 100644
--- a/src/model/resource/Purchasable.ts
+++ b/src/model/resource/Purchasable.ts
@@ -4,25 +4,36 @@ abstract class Purchasable implements IResource {
   public readonly resourceType = ResourceType.Infrastructure;
   public readonly max?: number = null;
   public value: number = 0;
-  public unlocked: boolean = false;
 
-  public clickText: string = "Purchase";
-  public clickDescription: string = null;
+  public clickText: string = 'Purchase';
+  public clickDescription: string = 'Purchase';
+
+  public cost: { [key: string]: number } = null;
+  protected _costMultiplier: { [key: string]: number } = null;
 
   constructor (
     public readonly name: string,
-    public readonly description: string,
-    private _cost: { [key: string]: number }
+    public readonly description: string
   ) { }
 
   public clickAction (state: GameState) {
     if (this.max !== null && this.value >= this.max) return;
-    if (state.deductCost(this._cost)) {
+    if (state.deductCost(this.cost)) {
       this.value += 1;
+      if (this._costMultiplier !== null
+        && Object.keys(this._costMultiplier !== null)) {
+        for (const rkey of Object.keys(this._costMultiplier)) {
+          this.cost[rkey] *= this._costMultiplier[rkey];
+        }
+      }
     }
   }
 
-  public advanceAction (time: number, state: GameState) {
-    // do nothing
+  public advanceAction (time: number, state: GameState): void {
+    return;
+  }
+
+  public isUnlocked (state: GameState): boolean {
+    return false;
   }
 }
diff --git a/src/model/resource/Religion.ts b/src/model/resource/Religion.ts
index 6635cc0..8e4af0e 100644
--- a/src/model/resource/Religion.ts
+++ b/src/model/resource/Religion.ts
@@ -3,16 +3,19 @@
 class Religion implements IResource {
   public readonly resourceType = ResourceType.Religion;
   public readonly max?: number = null;
-  public readonly unlocked = true;
   public readonly clickText: string = null;
   public readonly clickDescription: string = null;
   public readonly clickAction: () => void = null;
   public readonly advanceAction: (time: number) => void = null;
+  public readonly cost: { [key: string]: number } = null;
 
   constructor (
     public readonly name: string,
     public readonly description: string,
     public value: number,
-  ) {
+  ) { }
+
+  public isUnlocked (state: GameState): boolean {
+    return true;
   }
 }
diff --git a/src/model/resource/SavingsBonds.ts b/src/model/resource/SavingsBonds.ts
new file mode 100644
index 0000000..bff43fd
--- /dev/null
+++ b/src/model/resource/SavingsBonds.ts
@@ -0,0 +1,23 @@
+/// <reference path="./Purchasable.ts" />
+
+class SavingsBonds extends Purchasable {
+  public max?: number = null;
+  private _isUnlocked = false;
+
+  constructor (
+    public value: number,
+  ) {
+    super('Savings Bonds', 'Grows money by a small amount over time.');
+    this.cost = { 'money': 25 };
+    this._costMultiplier = { 'money': 1.1 };
+  }
+
+  public isUnlocked (state: GameState): boolean {
+    if (this._isUnlocked) return true;
+    if (state.getResource('money').value >= 25) {
+      this._isUnlocked = true;
+      return true;
+    }
+    return false;
+  }
+}
diff --git a/src/render/DebugRenderer.ts b/src/render/DebugRenderer.ts
index 6d0de8a..f74fec8 100644
--- a/src/render/DebugRenderer.ts
+++ b/src/render/DebugRenderer.ts
@@ -3,6 +3,7 @@
 
 class DebugRenderer implements IRenderer {
   private _initialized = false;
+  private _handleClick = true;
 
   public render (state: GameState) {
     const container = document.getElementById('irreligious-game');
@@ -11,15 +12,17 @@ class DebugRenderer implements IRenderer {
     } else {
       if (!this._initialized) {
         this._initialized = true;
+        state.onResourceClick.push(() => this._handleClick = true);
         const style = document.createElement('link');
         style.setAttribute('rel', 'stylesheet');
         style.setAttribute('href', 'css/debugger.css');
         const head = document.getElementsByTagName('head')[0];
         head.appendChild(style);
       }
-      for (const rkey of state.getResources()) {
+      const rkeys = state.getResources();
+      for (const rkey of rkeys) {
         const resource = state.getResource(rkey);
-        if (resource.unlocked) {
+        if (resource.isUnlocked(state)) {
           let el = document.getElementById(`r_${rkey}`);
           if (el === null) {
             el = document.createElement('div');
@@ -27,11 +30,14 @@ class DebugRenderer implements IRenderer {
             el.id = `r_${rkey}`;
             let content = `
               <span class='resourceTitle' title='${resource.description}'>${resource.name}</span><br>
-              <span class='value'></span><span class='max'></span>
+              <span class='value'></span><span class='max'></span><span class='inc'></span>
             `;
             if (resource.clickText !== null) {
               content += `<br><button class='btn' title='${resource.clickDescription}'>${resource.clickText}</button>`;
             }
+            if (resource.cost !== null && Object.keys(resource.cost) !== null) {
+              content += `<br>Cost: <span class='cost'></span>`;
+            }
             el.innerHTML = content;
             container.appendChild(el);
             if (resource.clickAction !== null) {
@@ -43,9 +49,31 @@ class DebugRenderer implements IRenderer {
           const elT = el.getElementsByClassName('max')[0];
           elV.innerHTML = this.formatNumber(resource.value, 1);
           elT.innerHTML = resource.max !== null ? ` / ${this.formatNumber(resource.max, 2)}` : '';
+          if (this._handleClick) {
+            const elC = el.getElementsByClassName('cost');
+            if (elC.length > 0) {
+              elC[0].innerHTML = this.getCostStr(resource, state);
+            }
+          }
+        }
+      }
+      this._handleClick = false;
+    }
+  }
+
+  private getCostStr (resource: IResource, state: GameState) {
+    let cost = '';
+    for (const rkey of state.getResources()) {
+      if (resource.cost[rkey] !== undefined) {
+        if (cost !== '') cost += ', ';
+        if (rkey === 'money') {
+          cost += `$${this.formatNumber(resource.cost[rkey], 1)}`;
+        } else {
+          cost += `${this.formatNumber(resource.cost[rkey], 1)} ${state.getResource(rkey).name}`;
         }
       }
     }
+    return cost;
   }
 
   private formatNumber (num: number, digits: number): string {