I really hope that the sole reason that michaelt concluded this is simply due on not having any experience how to manage credit card payments (on merchant's side).
For those who does not handle these things: I am not sure on what processor Network Time Foundation is using, but Stripe's $15 fee is actually on the low side of chargebacks (some processors even use the fixed fee + percentage model). Worse, this is unconditional: if you somehow won this, you won't get the chargeback fee.
You know what else costs money? When someone wants to give you money, and you misidentify them as a bot and refuse their money.