The market on west nanjing road is the best bet in SH. But you won't find good quality there. But still fun to go. There is a big store on the first floor. Go to the bottom left corner on that floor and ask for watches. The store is hidden.
Prices vary a lot. But I have payed 400rmb for all the watches I've bought there. They don't have anything worth more than 5-600 rmb. Not just that store but the entire "mall".
West nanjing road and Peoples square are the closest metro stops.
If you want good reps, Toro is the way to go.
He delivered 18 hours after I ordered, in Shanghai.