I just saw a jetski at my local Costco for $2k off list price. If you're a member it might be worth checking out their program -
http://www.costcoauto.com/boat/enter...2fdefault.aspx
Credit card fees can be 1-3% of the transaction. I'd use a check or cash for the best price.
I've had good luck using cash. Nothing says I'm ready to buy without a hassle like a stack of $100 bills.