As late as 2012-2015 it was still extremely cheap to get suits in HK, but I'm sure that's no longer the case.

The last time I did it, I bought fabric for $60 USD at Joann's, flew to HK, and gave a guy the fabric for a suit. The suit cost $45 USD to make.

I think, latterly, my dad was getting them made in Seoul and I had some clothing made there and Singapore as well. But I had admittedly not been in HK for years and years and didn't really need suits in any case.