For a more detailed cost comparison with PayPal:
Stripe's pricing starts at 2.4% + £0.20 per transaction + VAT. Stripe charges 2% for foreign conversions (i.e. charging in EUR, when you want to be paid out in GBP).
PayPal's pricing starts at 3.4% + £0.20 per transaction. In addition to their published rate, you'll also pay:
* £20 per month if you want to design and host your own checkout pages.
* If you process in other currencies other than your local currency, PayPal will charge you a fee of 2.5% above the wholesale exchange rate (https://www.paypal.com/uk/webapps/mpp/cross-border-and-conve...).
* If you receive payments from customers outside of the UK, PayPal will charge you a fee of anywhere from 0.4% to 1.5% (https://www.paypal.com/uk/webapps/mpp/cross-border-and-conve...).
* If your customers pay with American Express, PayPal will charge you a fee of 3.5%.
* If you issue a refund, you will pay a fixed fee portion of the original transaction fee.