In early May I was in both Phuket and Bangkok, and after a compact digital camera, I found that the selection wasn't as good in Phuket City and Patong as in Bangkok.
I think I went to almost all the camera shops in Phuket, the camera I was after was a pretty new model, stock was short and prices were about the same as Australia.
In Bangkok I went Panthip Plaza (Big electronic Plaza) and got a really good price on the camera I wanted, just be aware many cameras don't have an International warranties, warranty is local, only applies to country of purchase.
Bob Mac lives in Thailand so has some good advice to offer.
I was prepared to risk it....so far no problems
Good luck, hope this helps.