Your pricing page does not look right in Chrome 6.0.472.63 on Mac (latest current). Screen cap: http://i.imgur.com/ffxIy.png
As someone who will be looking for this type of service in the near future, I agree with Michah that the pricing for a start up, especially one that's bootstrapping is not attractive at all. At this pricing it makes more sense to build my billing system and use Authorize.net.