You can buy or unlock 80% apps from Google playstore. Here are the tips… First your phone must be rooted in order to use the software that does this magic.
1.Download Freedom app and Mobile unlocker app from play store or any android store.
3.Open mobile unlocker and enable the unlocker. Go to market and select Russia Federation.
4.Open your Freedom app and select any app you want to unlock or buy.
Comment if there is any other thing you want to know.