As mentioned most businesses have the CASH rate posted and 99% of the time it's better than the euro and CC rate but it's for cash. Not restaurants but the Super U is $1.15/euro and the Cadisco fuel station in Orient is still a marvelous $1/1 euro which is a BIG advantage for USD cash. I saw a $1.10 rate but forgot where

To get the best credit card rates the charge has to be billed in euro and let the bank convert. If billed in dollars the establishment will convert and bill the card....and neither beat cash if there is a cash discount posted

Well worth a visit to an ATM to get dollars....and your bank will convert. Just make sure you have a bank that reimburses for ATM fees. I used on in SImpson Bay (Winward) that charged a $7.50 fee per transaction