I found this thread very useful when researching Thai tailors. The gist of it is that you get what you pay for and there are some tailor recommendations that might help you.
My husband had 1 tuxedo, 2 suits, 2 extra suit pants and 5 shirts made for 20k THB. I think it was originally 4 shirts and 21k THB but they knocked it down a little bit and threw in another shirt. I’m sure we still got hardcore ripped but it came to a little over $900 (curse the shitty AUD) which is the price of one suit here.
He’s never really liked the fit of suits and shirts because he has broad shoulders and a regular waist but off the rack clothes seem to be made for people who are broad all over. With a tailor he could get everything fitted to his liking and it looks better than anything he could get here for the same price. He also liked being able to pick and choose the colours.
He’s worn them for a couple of months here and they still look good. He doesn’t think he got Saville Row quality or anything, but if you put him next to someone who bought his suit off the rack you can see a definite difference.
I bought a couple of suits when in Thailand back in 2001. One was a mediocre Pierre Cardin knockoff that I have yet to wear. The other is one that knock’s everyone’s socks off that is made out of the classic Thai Dragon silk. It’s pretty ostentatious and is a real hit on the rare occasions that I bust it out. I’ve only worn it two or three times, but I don’t suspect that it’ll last all that long. They both cost $100 (including a dress shirt and a tie) back then, so I’m sure if you paid more, you could get something higher quality.