Why is this surprising? Everyone who accepts credit cards has to deal with processing fees, fraud prevention, chargebacks, etc. And at a larger scale they need to deal with lawyers and contracts.
Most likely. It appears to be around 5% of this years budget. It’s typical to pay 2-3.6% in CC fees alone plus often a transaction fee of 10-30c which can add up on small $1-$5 donations (30c is 6% of $5 and much more of $1).
They may have raised more or less than their annual budget this year plus I imagine probably spend some money on their email campaigns etc.