Update on Barbados - there are a few single engine airplanes here now - a 152 (Barbados Reg), a 172 SP (Barbados reg), a PA32 (Cherokee Six - US reg) and soon my PA28-181 (US reg) will be back.
To fly Barbados registered airplanes solo one can do so in Barbados airspace on any ICAO licence (so UK, US, EASA etc), but to fly solo to other islands one needs a Barbados license (on the 2 of 3 rule); US registered airplanes one needs to have a US license (although with a Barbados license one can fly in Barbados airspace - the 2 out of 3 rule again) - with a UK, EASA etc one can get a piggy-back FAA licence that is good while your original licence is valid (there are threads about getting one on here).
The cost tends to be US$200-300 per tacho hour (reflecting the cost of 100LL and the low usage on the airplanes), an hour gets one to Bequia, Mustique, Canouan, St. Lucia so a couple of hours for a trip. There are no landing fees in Barbados - so one can have fun flying circuits with the big Airbuses and Boeings (real wake avoidance!) landing fees and other levies are payable at other airports in the region. Most flights require a check out - a good thing for the local procedures and the comfort of having an instructor along while one attunes to the accent on the RT - a instructor will run about US$35-45 per hour and a check out normally takes maybe 30-45 minutes.