Costs
My costs in Wuppertal are of course very different from those of a tourist in Wuppertal. I don't pay accommodation costs, but I do pay rent (incidentally, rents in Wuppertal are still comparatively cheap). I eat out less often, but I cook more.
However, I wouldn't describe Wuppertal as an expensive city. The cost of eating and drinking out is cheaper than in other big cities such as Cologne or Düsseldorf. Accommodation costs are also somewhat cheaper.