The famous Shanghai "Fabric Market" is home to hundreds of shops selling bespoke suits, dresses, and more, and is the city's prime destination for custom clothing garments. You can also pick up a ton of interesting fabrics here if you're into DIY. If it can be stitched and sewn, they can probably do it for you at the South Bund Fabric Market, including alterations. The place is spread across several floors and prices can go down a bit the higher you go. The amount of material choices can be overwhelming so it would be helpful to go with someone who understands fabric if at all possible (i.e., someone who can tell if it's a cheap polyester blend trying to pass as wool). For a real cheap two-piece suit, you're probably looking at 500-800rmb and roughly a week, though they can add speed for a fee (in our experience, you'll need two fittings). For something a bit better, expect to pay around 1,000-1500rmb, though if you're going to spend more than that, you really should know what you're doing, otherwise you'd be better off getting something from a trusted brand off the rack and altered. Custom shirts will start at 100-200rmb depending on material. Quality can vary wildly, even in the same shop, so it pays to shop around. Payment is mostly in cash, WeChat or Alipay; a lot of vendors don't accept cards, but there are ATMs there. Most of the shops have English names, and you might wanna ask an old head around town if they've got a recommendation for an auntie or uncle there.