I don't collect things physically unless they're rare and really cheap. I have a few cels but they're absorbed with dust, sitting on a stack of old greasy papers, because I don't take care of my stuff. Although most of the cels are from shows no one cares about, so it's all good. Personally I think cels are better suited for a museum. If I don't die prematurely, I'll try to give all my older stuff to museums/groups that preserve old things. Hopefully cel museums exist by then.