If it's a hobby through which you can make a few gear tokens, go for it. A business, I think you'd struggle, it's not just the margins on parts versus sold instruments which would be low, but the time costs of all those discussion with interested buyers who eventually decide on a Sire. I've built some bitsas to order here and made a loss each time, and that loss doesn't include the time I spent. OK, I wasn't doing it to make money, but neither did I sell any of the instruments below its value as an instrument. iI guess I'm saying that as a bobby that might wash its face, fine, as a business, no way