Having just come from Hoi An and after visits to numerous tailor shops, my view is that don't bother. Those so called 'tailors' don't have a clue. If you end up having a 'suit' made for $120, you will be laughed at in your office in Sydney, London or Singapore. The quality of the materials, workmanship and measuring skills are so poor that you will look like a complete goose wearing those outfits. If you must part with your hard earned USD's, may I suggest you could do worse than just drop $120 in the donation box at the Hoi An orphanage. Save yourself the embarrasment and please resist the urge to have anything made.
The fabrics are all fakes as well. Do you actually believe "Louis Vuitton", "Pierre Cardin" and "Versace" actually sell bolts of fine merino Super 150 cashemere/wool cloth to those untrained tailors in Hoi An, only for the tailor to then sell you a suit for $120?? If it was genuine Italian / English cloth, the material alone needed for a suit would cost $400.
Does any actually understand the skill and effort needed to tailor a men's suit jacket? It takes years of training to learn to properly measure up, cut the cloth, make the pattern, understand the layering of the padding, stich up and finely adjust. The Hoi An tailors complete this process in a nearby sweatshop in 6 hours. Just ridiculous.
Not everyone needs to spend $6,000 on a Saville Row masterpiece. If you need a decent suit which you can wear to work, then go to Hong Kong where a number of well trained Cantonese tailors can make you a suit for $600. They will also have proper chest and shoulder padding and will give you at least 2 fittings.
I had a "suit" made by Impressions Boutique in Hoi An. It was so poor (my 12 year old daughter could have made a better suit), I demanded a refund and got one. It was unwearable.