Set a service fee for accepting CC on orders for less than $10.   Or, all orders on the cart.  how many order does one get that are $30 or $40?  It could be waved for large orders.    …… Processing fee plus a percentage, say 75 cents or $1.   Then it is the customer’s choice. 

 … If most of your sells are $8 to $15, you may be slightly behind on your CC cost, but the difference should reasonable & acceptable.  If your sells are small then you should be a little ahead on CC cost.

Remember not long ago, many business had two prices cash & CC.