As with any website, there is an ongoing fee for hosting which is under about $27 per month if using Hostek
We also strongly recommend that you get an autoresponder
Another fee will be your merchant account charges. Typically a merchant account provider takes between 2.5% and 3.5% per transaction.
One other fee to keep in mind is an SSL certificate for your site. This is what encrypts your credit card pages. An SSL certificate costs about $129 per year.