There are a few blocks of shopping in downtown San Andres.  Not everyone speaks English.  Plan your shopping around the town's siesta break, which starts at 1 P.M., when virtually EVERY store shuts down completely.  The signs in the shop windows say the stores will re-open at 3 P.M., but many do not re-open until 3:30 P.M.

This town used to depend heavily upon "duty free" shopping and the stores reflect that history.  These are store you would mainly would find in towns which are heavily visited by cruise ships.  There are lots of "knock off" stores of jewelry, clothing and electronic goods.  A few souvenir shops but not as many as you would expect.  Most shops are very small and  specialize in one type of good.  The majority of shoppers are Colombian and the goods will be targeted towards them.  Each store decides on their own rate of Peso to U.S. Dollars exchange.  Ask what rate the shop is using before you begin your purchase.

 If you search carefully you will find several places where the locals have set up small artisan shops where the goods are often the same as the bigger more established shops but they can be purchased for less and you can often bargain for the best deal. 

There is at least one large market in town which can be handy for packing lunches to explore the rest of the island.  There are several "pharmacies" which will sell you most medications you may need.  These pharmacies also carry some snacks, drinks and alcohol.