When I was more active in it, I used to come across prosthesis and other disability fetishes in the BDSM scene. Not something I played with, but knew it was out there through the occasional person/conversation. I've even come across a few medical fetish websites that sell prosthetics for non-medical purposes (basically for people who don't need them to pretend like they do.) It's kind of one of the many dark alleys in the Kink world-weird even by kinky standards, but accepted as long as it doesn't go to the point of actually hacking anyone's limbs off.
With fetishes like this, the presence of the fetish frequently more important than what more vanilla individuals would consider heavy sexual activity, hence her ability to simply sell her fetish, and nothing more. I'd say this lady has done a fantastic job of cornering a niche market-I can't imagine there are too many others out there in similar situations willing to provide.