There's a lot of things that can be economically viable at the personal/household scale that can't work at the commercial scale because of the regulatory requir

There's a lot of things that can be economically viable at the personal/household scale that can't work at the commercial scale because of the regulatory requirements of a modern first world workplace. Most of the time when you see a kit to DIY something this is the niche in which it lives. Not saying the economics work out for this particular thing but just because it's not commercially viable doesn't mean it's not economically viable. You don't see scrapyards hiring people to drive around picking up scrap metal yet people do it for a net profit, same concept.