It all depends on the company you choose, but you will probably pay a gateway fee, statement fee, virtual terminal lease (if you don't buy the software), a transaction fee of around a quarter each, and then the discount rate, which just means the % of the purchase that they keep. Usually that's around 2-4%. Overall it'll run you around $60 a month or so (not counting the discount rate and transaction fee).
I'm sure there are plenty that charge less out there, but it is so mind numbing it's hard to keep up with!
