In App-billing Implementation , Buying Paid App From Free Version

I have paid and free version application in the single publisher account. now I have implemented the in-app billing implementation in free version I have added the in app product a

Solution 1:

You can not add any other app like "in-app purchase". In your case there is two possibilities:

1. Redirect user to market. In this case you have to provide sharing data between apps (like progress in a game or something, that was done in free version)

2. You can provide all possibilities in "free" version, and lock it, while user does not buy "unlock full version" purchase.

More info can be found here.