Prices are all reasonable. Remember, for big ticket items like scuba, tours etc, the prices are usually $USD. Restaraunt menues listed on teh web (a most fantastic ting about AC's web) are usually in $BZ which are double $USD. In otherwords, cut it in half.
For a great moderate night you must stop at Jade Garden. Bike ride to Basils for another moderate lunch. For inexpensive, my opinion is almost anywhere in town. The first day there, walk around and check out the places and the prices. It's a great first day to walk around, see the town and check out the places and prices. Bring a small pocket note pad. I
'd tell you my favorites but they are in the basic price range for AC ($4US for a meal) and there are so many I haven't tried it's not good for me to name them. Plus, I don't want them crowded!
You'll be fine.