[outcoldman]

If you really want to make $10 from a user, you just charge them $12.99. No need for Subscriptions.

[mk89]

If you want to make 10$ you need to sell it for 14.29$ because the 30% is taken from the total. (30% of 14.29 = 4.29).

Anyway, that's beyond the point. You need to find a way to support your development also for the next years.