I was looking into this for myself. I came across a program that drafts to be the perfect fir for your own body. Meaning it's a custom pattern to your own body and not the market standard.
You put in like 30+ measurements (60+ if working on the Pro system), but it's for your own body (maybe even a client)
Would it be something people would be interested in? I think I would offer them for not more then $5 (was thinking $2 before, but after reading on the fees Esty and Paypal take, I took it up a little)