I see a lot of people who complains about the kuponut/coin payment for the usage of the MB in the app, and while I do understand why it is there I do agree that it is a little too steep. My suggestion is to instead of one kupo-nut giving one transaction it should give the player 1h access to doing MB transactions. By doing this you make it realistic for people to use the app to handle their MB needs while they are at breaks at school or at work while still forcing people who are looking to use it all the time as a substitute to log into the game to pay up money for further usage.
This system would also make it feel worthwhile for people to both sub for the extra kupo-nut per day, but also to buy further usages for when they are on trips, etc as it would offer them better value for their money.