Stripe & Gumroad offer transaction fees. Here's a quick overview of each.

STRIPE:

1.4%+20p for European cards

2.9% + 20p for non-European cards

GUMROAD:

For free accounts, the fee we take on each sale is just 8.5% + $0.30 (USD) per sale. That means, no matter what, you keep the vast majority of the proceeds – as you deserve.

Gumroad’s premium features start at $10/month (or $108/year), and the feetaken on each sale shrinks to just 3.5% + $0.30 (USD) per sale.