I’ve tried Payhip, and it works wonderfully for embedded “Add to cart” button and direct buying buttons (similar to Gumroad). There’s a small fee on every purchase, but no minimum monthly fee like Snipcart.
Only downside: no CSS customization for the embedded cart as of yet.
If you make between $260 – $5,000 in sales per month: stick with Snipcart.
Over $5,000: switch to Payhip Pro.