I agree with everyone that it is very difficult to make money back on a kit or scratch build, even with great hardware.

Having said that, I definitely agree with HereIsJT that where there is a will there is a way, and that as long as you work backwards from the obvious constraint of maximum sale price (dictated by market) you can then try to find creative solutions to increase the difference between what you outlay and what you get back. I don't think it's going to be easy, but your age is on your side and you have the right attitude to give it a crack.

The art world suffers from a similar predicament. It has taken me ten years to start making money back on my paintings, because everyone charges the artist and no one pays. Materials, time, framing, freight, tax, etc and then no guarantee of a sale. It's really killer.

Having said that, I think McCreed actually landed on a solution (which also works for artists). Commissions are a great way to guarantee you will make money, because you don't spend anything until you get the job. You can ask for a deposit that covers materials, and then even if they fall through on the final sale you aren't out of pocket except for time, but if you sell it at a discounted rate after that you're still ahead.

The other great thing about commissions is people come to you because they like your style, as opposed to you making something great but then the sales process being at the mercy of whoever is on your local FB marketplace. It takes time to build a reputation, but that is true either way, and you'll starve less in the meantime!

The other thing artists often do is form collectives to share overheads. I have some friends who have started this amazing woodwork/printing/fabrication workshop. Basically they hired a huge shed and pooled their resources to fill it with gear they either already had, or bought cheap, or scrounged. They are all making completely different things, but they all have their own space, access to a crazy range of gear, and they share the costs so each person is paying a reasonable amount. They also hire gear out to make money back. It's a really good model if you have some friends who also want to build things