I suppose if you wanted to, you could put some money into buying gasket kits, pipes, etc and then figuring out ways to replicate them at home. Then you could offer your homebuilt gasket kits at a cheaper price, and I think people on 3ww would be more likely to buy them if they were equal quality, and the money stayed inside the triking community. You can home-make sectional pipes, people are always wanting to make more power on their trikes. Keep some good quality DG or stock pipes laying around for reference and build off of that.
Personally, I think CONVERSION
parts are where it's at right now and in the future. If you can make kits that make it possible to, oh I don't know, use a Banshee axle on your Tri-Z, or a set of TTR-250 forks, or SOMETHING, that's probably well worth the time and effort it will take to research and make the small changes. You can buy Banshee stuff dirt cheap, as with most quad
parts. Machine out the stuff that's in the way until it fits in a Tri-Z carrier and walaa you've got an almost endless source for axles. And so on and so forth!