We have a bar here that organizes LARP (Live Action Role Playing). People dressing up for that often really look GREAT in their costumes, because they are not trying to copy someone. If you try to cop ysomeone, you need the stature, the physical build, so there are some natural limits right there.
Personally, I am neither a LARPer nor a Cosplayer, but I played several NPCs already in the last LARPs - a Demon (who cleverly disguised himself as a spice merchant with a large, unexplained battle axe), a strange whisper originating from an amulet and the god of awkward beards - and I have to say that it is fun. My costumes were about 15€ all together, and they were pretty bland, but with a well-made costume I think it would have looked really good. Personally I wouldn't buy one, go to LARPs as a player or do Cosplay, but if the tailor knows his craft, I think it could be really worth a pretty penny.