Hángzhōu is famous for its silks and there are certainly bargains to be found in this seven-storey market. You'll have to work hard to get them, though. Head straight for the 5th and 6th floors (lower levels just sell regular clothes) to find scarves, slinky nightwear, dresses, qìpào (traditional Chinese sheath dresses) and other silk items. If you haggle with persistence, vendors will usually let you bargain them down by around 30%.
There's plenty of polyester in the mix at this market, so examine material carefully before you make a purchase.