That is kind of why I am doing my build a piece at a time and using what I have, or have been collecting literally for at least 35 years. Lots of estate sale camping gear, lower to mid range stuff modded to fit my specific needs etc...
Before I am ready to hit the trails, I likely will have another $10K sunk into it, but I am going through a total engine overhaul, gears, some body work due to failed door hardware for my backdoors which is common on SuperCabs...
Honestly, I would be money way ahead just buying a similar vintage Silverado, but I would be back at square one. Probably make it just about even by the time the winch is mounted etc...
It's honestly a pity Isuzu stopped selling in the US. I actually liked the Rodeo. A female friend (NOT girlfriend) I knew before I met my wife had one. It was actually a shockingly competent off roader considering it was so cheap and cushy for its era.... She could almsot keep up with my CJ-7...
Honestly that is one way to drive costs down, start with less popular 4x4 models. Isuzus, 90s / early 2000s Nissan, Mitsubishi etc...