iOS In App Purchase: test a real purchase without submitting to Apple

Short answer: you can't test a real purchase (aka, spend real money). It isn't possible.

Slightly longer answer: You'll automatically hit the sandbox environment unless it's an apple-signed release build. Even ad-hoc signed builds hit the sandbox.

To test a new IAP: create your IAP (it will be in "needs approval mode" until submitted with the final build and test against the sandbox - that's fine). If your purchase works against the sandbox, it should work against prod with real money as well. It would be great to do a trial run with real money, but that's just not possible until the IAP is approved and you get the production signed version of the app from the app store.

You can actually test the in-app purchasing in the sandbox environment, basically you'll need to set up an test user account in your iTunesConnect.

Check the apple documentation here: http://developer.apple.com/library/ios/#technotes/tn2259/_index.html

You'll be able to find all the information related to In-App Purchasing, including sandbox testing.

Just create a test account on iTunes Connect. Then log out from the device and run your app from Xcode.