If you have already implemented Google's in-app billing version 3 method, by following these 4 easy steps, you will be able to use
Bazaar's in-app billing services.
1. Edit AndroidManifest.java
change this line:

<uses-permission android:name="com.android.vending.BILLING" />

to this:

<uses-permission android:name="com.farsitel.bazaar.permission.PAY_THROUGH_BAZAAR"/>

2. Edit IabHelper.java
find this line:

Intent serviceIntent = new Intent("com.android.vending.billing.InAppBillingService.BIND");

and change it to:

Intent serviceIntent = new Intent("ir.cafebazaar.pardakht.InAppBillingService.BIND");

3. Obtaining the Public Key (RSA Key) for the Application
Go to CafeBazaar's developers' panel. Upload your apk, but don’t submit app review request.

Go to Dealer Apps page. By clicking on the RSA Key in the Actions tab, Base64-encoded RSA public
key for the application will be shown.
This code is your new base64EncodedPublicKey string which you can replace it with the one you got from Google Play's developer console.
4. Defining your products and their SKUs in Bazaar's panel
In developers' panel under the Applications tab, click on the Enter button related to your app. Go to Products/Services page. You can add your in-app products with your unique SKUs.