http://www.fitnessshop24.ch
I'm off to this place in a bout 10 mins to get a dumbell set and then a bench a few days later, don't know how cheap it is but 5 min walk from where I live so for convenience it will do.
go out from wiedikon station and turn left (ie go round the back past the bus stops), then turn left on the main road (Zweistrasse)