Well, I do a couple of websites gratis for nonprofits, such as
http://servecitychosen.org/. It’s pretty simple to add a payment method using PayPal. Cost is 2.9% + $0.30 per transaction for low volume use. Payments go directly to your bank account.
I think this would be great, and so convenient for everyone. They can even add the Paypal fees back on for folks opting to pay that way, I know I'd gladly pay the extra couple $$. I use PayPal for Ebay and have never had an issue.