How do you get the in app purchases for free?

first use cydia to look up ifile then go to the "user" after that go to "applications" then numbers for eg : 00BEA0C8...-30C6C547E567 then look for (in any) itunesMetadata then tap text viewer then look for your iTunes account and it will show how much you have there then tap edit and replace the number of your actual itunes credit to for eg $9000 after that save it