I'd like to create a site that allows my customers to pay the invoices from me. This can be as easy as a invoice number, a custom price box, and a payment option.

Right now my only option to do this is e-commerce hosting I believe. But it's ungodly expensive to give this option to my customers. I'm not a high traffic online store, so it would be nice to have cheaper options for such a feature. I'd certainly pay more than normal hosting, but $300/mo to support an optional payment method through our own website is way too high.

Thanks