Merchant account options for Ruby On Rails ecommerce site

Question

I am looking for a payment processing solution for my Rails e-commerce site, here are my requirements.

1. Simple Rails integration, e.g through activemerchant plugin.
2. Operates in the UK.
3. Payments can be taken on my site (not redirected to third party)
4. Preferably no/low monthly cost, and therefore higher transaction percentage for when site first goes live.

Thanks

Answer 1

http://activemerchant.rubyforge.org/ lists the available UK gateways (covering your points 1 & 2)

Point 3 is why I'm posting though. It's likely that hosting the payment page yourself will mean you're going to need to be PCI-DSS compliant, which will be worth looking into if you aren't already aware of it. In short - you may want to reconsider!

Point 4 I can't personally help with. You'd need to query the providers individually to weigh up costs/benefits.