The local currency is the Bahamian dollar BSD, but it's tied to the US dollar at a 1:1 ratio and US dollars are accepted everywhere at par. There is thus no need for Americans to change money, and many tourist-oriented businesses will even give change back in US$. Do keep an eye out for the famous but now rare three-dollar bill and 15-cent coin, both originally made to ease the 1966 transition from British pounds to dollars, $3 being roughly equivalent to £1 and $0.15 approximating a shilling. If you are coming from Bermuda, East Timor, or Panama, you will also find that the Bermudan Dollar, East Timor Centavo, and Panamanian Balboa coins are in equal value to the Bahamian dollar, but you will still need to exchange your currencies. But understanding the prices will not be a problem.
All the usual Caribbean luxury retailers are found in Nassau and Freeport, including both stand-alone boutiques for international luxury brands as well as regional Caribbean retailers that specialize in representing multiple brands.
There is very little made in the Bahamas, but some luxury goods can be purchased at a bargain, although you should do your research in advance and make sure you can properly import any purchases under your home country's duty-free allowance.
On 1 Jan 2015, the Bahamas replaced the 10% Hotel Guest Tax with a broad-based 7.5% Value Added Tax VAT. Because the Hotel Guest Tax primarily targeted tourists and the VAT targets both tourists and locals, you can't get a refund for it.
Salespeople in the Straw Markets arts and crafts markets have a very direct but often humorous manner of negotiating the price of a product. A sense of humour is greatly appreciated in this island nation.
Groceries including fresh fruits and vegetables must be imported see the "Eat" section below and are very expensive. Most brands are similar to those found in the mainland United States but certain UK and European brands are also available. Some brands are found primarily in their Caribbean/South American versions i.e., Kit Kat instead of their U.S. version. U.S. tourists may be shocked to realize that prices are similar to those of Aruba or other remote destinations in the southern Caribbean, even though the Bahamas sit just off the Florida coast.
Beware of purchasing Cuban cigars. The vast majority of "Cubans" for sale in the Bahamas are counterfeit. Only buy cigars from reputable and dedicated tobacconists, do not buy on the street, in the market, or from rinky-dink combination cigar/liquor shops. Real Cubans cost upwards of USD30 per cigar. If the price is $10, it's 100% fauxhiba. If you do plan to buy cigars, some online research may assist you in identifying authentic Cubans. The Ultimate Counterfeit Cuban Cigar Primer (http://www.cigarnexus.com...) and The Havana Journal Counterfeit vs Real Cohibas (http://havanajournal.com/...) pages may be particularly useful to you.