Any other places i should consider for trip at beginning of december?

[Hintermann]

Currently looking at liveaboards in Thailand, Red Sea or St Martin to St Kitts.

Trying to keep the budget under 2500$ for the week with flights from Toronto/Buffalo

If you mean Canadian $2500 including the flights, only the Red Sea liveboards would be within that budget. You might get away with a Caribbean one with flights if you manage to catch a discount offer and/or cheap flights. But land based diving like a week in Cozumel might be achieved for that money as long as you avoid the expensive all inclusives and go for a package with Aqua Safari and similar outfits.

But your options are greatly increased if the C$2500 was your budget for the liveaboard week per se. Phuket liveaboards tend to be competitively priced and December is a good time to dive there.

 

[Dannybot]

Look at Cozumel, $900-1000 single all inclusive at Hotel Cozumel diving included. Tips $250, that leaves $1250 for airfare. There are plenty of ops and room/diving packages in that price range. I like Hotel Cozumel for the economy, access to dive shop and just 1/2 mile walk to downtown.

it's not valet diving, but most DM's will show all sorts of stuff, and keep you safe. I also like the relaxed pace of the big boats. The resort is just a place to wash, sleep and eat for me.