Larry - No worries, credit cards are widely accepted on both sides of the island, Visa, M/C & Amex. Always carrry at least two cards and use the same one card for hotel & car rental and the other for the remaining charges.
Some French side restaurants are still offering 1:1 exchange but there are not as many as before and you'll have to seek them out, many post their menu on the front door or outside on a board, this offer is for cash or traveler's checks only, not for credit cards.
Many banks and credit cards will charge you a fee for foreign exchange (maybe up to 3%) and a lesser fee if billed in USD. There is no fee for travelers checks use. The Dutch side will always bill in USD and the exchange is pegged to the USD at NAf 1.778. Some vendors may vary slightly from this amount.
Inexpensive dining other than American fast food places:
Lolos - look for these roadside or beachside BBQ type grills that serve ribs, chicken, fish for bargain prices.
La Croissanterie in Marina Port La Royale, Marigot offers 1:1 for breakfast & lunch, great croissants & sandwiches and more. American & French style breakfast.
La Petite Auberge des Iles - A complete French dinner for about $30.00 p.p., also in the Marina mentioned above.
Pizza Pasta - In the Maho complex behind Cheri's Cafe offering excellent Italian fare for modest prices.
Le Piment - Orient Village Square - Pizza & pasta at modest prices.
Zee Best - Simpson Bay Plaza del Lago, great breakfast & lunch place.
Also, Boathouse, Hideaway, Bavaria, Le Bec Fin, Kangaroo Court, Chesterfield's are good choices.
Outdoors walking and hiking - visit Loterie Farm
Photos: Ft. Louis in Marigot, Ft. Amsterdam in Little Bay are just two, you'll find more as you travel about.
A car is needed to explore the many fine beaches, duty free shopping in Philipsburg & Marigot, dining and casino action.