Well first, study the irs tax code and become an expert at it. Then master quantum physics. If you can do that, you have a chance to begin to unravel the credit card fee schedule. Seriously though, they go out of their way to make it extremely difficult to compare rates. In general, you can expect to pay between 2.5 and 4 percent of your sales to your credit card processor. This will vary based on sales volume, average ticket price, percent of swiped versus keyed transactions, and depending on how good of a deal you negotiate. As much as I hate to pay them, It has become a necessary evil in todays society.