PayPal Fees
As the president of my son's high school marching band booster organization, a registered 501 (c) tax-exempt nonprofit, I can tell you that we pay 2.2% + 30 cents per transaction for accepting funds through PayPal. The standard rate is 2.9% + 30 cents per transaction.
If a for-profit collected $90,000 through PayPal, the base perdentage fee would be $2,610, plus the number of transactions times 30 cents. Even if you assumed an average of $20.00 per donation, or 4,500 transactions, that still only adds another $1,350 for a total fee of $3,960.