I have a friend, who also owns a very successful detail shop, that owns a credit card processing company. I'll buy my mobile unit through him soon. He gave me lots of information about how they "get" you signed.
They will project higher than avg. sales and then charge you more per transaction and take higher percentages of sales when you don't meet those numbers. He charges a set price and monthly charge is less than most.
I have used Nova and Authorize.net for years on my online store, but will get the Nurit 8020 soon for detailing and know that I am dealing with an honest and reliable person.
His detail shop is:
Spokane Auto Detailing & Spokane Window Tinting Bob is his name. Great guy with years of experience in cc business.
Hope that helps... Rob Regan