I also am a huge supporter of DIY projects. Also a huge fan of medium-format, film photography.
To that end, if I can help others try medium format film, I want to add that there are plenty of inexpensive used medium-format cameras on eBay. I have purchased perhaps a dozen over the years—none of which even approached US $1000. In case you are not DIY inclined…
(Sadly, Japan has been the best place to order used camera gear but that has become cost prohibitive now for this American.)
Searching just now on eBay for "Yaschica TLR Mint" shows a number of cameras around $300 that are probably excellent (surprise, most are from Japan).
Can't afford a Hasselblad? Try "Bronica Mint" on eBay. Looks like $500 will get you in the game.
Mamiya cameras are built like tanks (and weigh as much). You could do a lot worse: "Mamiya Mint" is going to get you a few great models around $400 or so.
All of these were (are) considered damn fine film cameras.
(Mamiya tend to have interchangeable lenses, as does the Bronica. There are some Wide/Tele adapters for the Yashica, but generally you use them as-is. Most of these cameras are completely manual in operation—the more sought after Yashica though have some light-metering capabilities.)
(The Yashica and some of the Mamiya are TLR, twin-lens reflex—more or less equivalent to a rangefinder? The Bronica and some Mamiya you view through the lens 'TTL'.)