We are seriously considering accepting credit cards. We currently have an on-site ATM. The ATM charges $2.75 per transaction So, a credit card fee of 3% will be a minor adjustment.  A $50 green fee is now $51.50 or $1.50 charge so it would be a reduction for those customers. 
Secondly, I often see that the card price is the base price and the cash price is the discount price. Instead of the card price being more..  Perception