Hello! I'll be staying at Shangrila, Pudong, Shanghai... Where can I go for 2nd hand cameras? Thanks!

The biggest 2nd hand cameras market is the Xingguang Photographic Equipments at No. 300, Luban Road, Luwan District. It is a little bit far from your hotel.
From your hotel, you need to walk to reach Huamu Road Subway Station of line 7 to reach Dongan Road Station where you can change to line 4 to reach Luban Road Station. Get out of the station from Exit 1, you can walk along Luban Road to reach that market. You may reach there is about 40 to 50 minutes.