You seem to have done your research pretty well.
I can't really help on the really cheap side of things but a few friends of mine went there several years ago and just arrived and worked it out from there with no real problems.
There are a couple of bars on the island and a disco were the local kids go.
With regard to DIY you can get a taxi to different islands. Kraski for example has a beach that is probably a couple of miles long. At one end there are tourists at the other end it is deserted. You can however catch bonefish in front of beautiful sparsely clad italian girls.
Last edited by petevicar; 01-23-2011 at 11:50 AM.