Since January 1st 2017 Russian players pay 18% VAT on digital purchases.
Unfortunatelly Google didn’t implement this correctly and it added the Russian VAT on top of the price that was displayed in game.
Today, 11 months later, Google finally fixed this issue!
This means the price displayed in the game and the price Russian users have to pay for Rubies and castle skins should be the same now.
The final price of all in-app-products are about the same as before.