Stripe
Stripe gives you a Merchant Account and Gateway in one. That way you don't have to handle sensitive card data, and you can get started without setting up your own merchant account. Stripe lets you collect payments and push the money to your own account, without your needing to store credit card information.
You have to use SSL encryption on your site to collect the information (which means you need a private IP), but you don't have to worry about storing credit cards and PCI compliance requirements.
Support:
24/7 support is available via email and in an open chat room that is sometimes staffed by their team, though
mostly intended as a forum for Stripe users to chat with each other publicly. They do their best to respond
within 48 hours, typically.
Pricing:
Refer to Stripe's website for up-to-date pricing. There are no monthly
fees, and no refund costs.
It's a better alternative to PayPal - not only because you don't have to redirect users to another site, but the pricing is simpler. PayPal has additional fees, like international payments and a fixed fee portion of the original transaction fee when you issue a refund.
Price
Available with Starter plan and above.