Thanks! And it does actually. I basically set all messages prior to the 50 cent value being hit as free just to promote early engagement and prevent transaction failures (Stripe suggest $0.50 as a minimum). But generally speaking, their (online transaction) fees are 2.9% + $0.30 so there's solid headroom.

I've got lots of features on both the frontend and backend to prevent automated behavior that could be problematic. But ultimately nothing is stopping someone from throwing a random number into the payment modal to see if it works (though they'd still have to enter an email, zip, expiration, and CVV too).