How many people would pay 70$ for a mobile game? I'm thinking way less than those you can get hooked on microtransactions.
My kids did that. I gave them a debit card with some allowance and next thing I know, $50 was spent on a micro transaction. $5, $7 and then a few more clicks, $50.
Google policy is they only refund the last transaction 1 time for an app.