I think something like this would work best as something that covers the greater cosplay/costuming world rather than just Star Wars specific, essentially a niche-targeted version of Etsy with it's search and item categorization specifically targeted towards one product segment (as the one avenue that etsy is horrible at for props is it's search, searching 'boba fett helmet' is just as likely to get you a laser-etched drink coaster as it is to give you an actual helmet kit).
But at that point you're looking at a pretty big company idea that will require a lot of startup costs, and would also be a pretty big legal nightmare, not only from potential copywrite holder DMCA's, but also complications arriving from if you want to offer an escrow service for pre-order runs and the like too. I actually suspect that Etsy purposefully keeps their prop categories and search so **** specifically so their cosplay market kinda stays under the radar and they don't become too known as a hub for it, they don't wanna deal with the legality of it too much either.
