I'm looking for a turnkey wifi hotspot solution that will throw up a captive portal, accept credit cards, and pay me if anyone uses it. What options are there? I know Tomizone used to do this but if they still do their website is pretty quiet about it.

Bonus points if if I can use existing hardware and the monthly fee is low or zero. This is for an experiment that may come to nothing so I don't want to end up out of pocket.