CheddarGetter does not require a merchant account or gateway while kicking the tires or while you are in the development or testing phase. You will need a merchant account and gateway before you accept real money but the two processes can run concurrently.

Yup, we started writing to the CheddarGetter API immediately for ScheduleThing. All of the payment gateway stuff is simulated nicely until you're ready to go live.

If I'm not mistaken, the kickstart is a limited offer and costs you $699 up front. That's difficult to swallow for most bootstrapped startups.

Spreedly has a per-transaction percentage charge on top of all the other per-transaction fees you pay to the gateway/bank/etc. Not a great option long-term. http://cheddargetter.com and http://chargify.com are much better options. CheddarGetter is a very robust service with usage tracking, branded email communication and microbilling features. Chargify includes a drop-in generic interface like Spreedly.

CheddarGetter does much more than recurring billing: branded fully customizable email communication, transaction error management automation, usage tracking, overage charges, microbilling, analytics. Free to try. No merchant account required during development.