If you want to save some cash, you could always try here in Phuket
Thailand, the diving is great, and since the Tsunami, everyone has
dropped their prices in a big way to try to get people coming back
here.
You should also be able to get a great deal on one of the liveaboards
to the Similan Islands, and Richelieu rock, if that appeals to you,
just be careful what ones you book on, its not always clear from the
price what's good and what's not.
All the websites look fantastic, but when you are stuck on a boat for
3-5 days its not so hot that your DM or Guide doesn't speak any
language that YOU have ever heard, or that the food sucks, Equipment is
crap, Etc.
If you need a point in the right direction, feel free to E-Mail me, I
don't think I will be here anymore by then, but I have been on most
of the boats here quite a bit over the past five years.
Cheers
D Vince