Quickbooks is the cheapest one out there but you still have to pay a transaction fee.
There is a reason why most places require a minimum to use your card.
Instead, look for the processor that will give you the most protection or is the best fit for your business.
The fees are a business write off, so while it make sting at first, there is a benefit to them as well.
You can't escape them so might as well get the perks you need!