'the most expensive project bikes are the free ones'
ask how i know this... lol.
However, doing spreadsheets and cost analysis, pfft, takes the fun out of it.
Buy whatever turns you on, is the most complete, and you think you would enjoy. If oyu start taking resale costs into it, etc, don't bother then. You'll always be making concessions and either half-ass it or get depressed about it. Look at it like any other past time. Does anybody do spreadsheets and cost analysis on watching sports? (aside from betting and fantasy teams).? no, they do it because they love it. Thats how I approach projects. Ive owned well over 100 bikes in the past 27 years. Ive bought stuff i wasn't familiar with and learned. I didn't like the way certain things were done and re-engineered them. to me, that's the fun. the ONLY bike i ever regret buying was an early honda XL175, it was pure garbage. to the point, after it dropped the second valve i literally left it at the recycling center. (some kids were dragging it into their dads truck as i was leaving, it was nice looking). But point is, have fun with the project. Buy what YOU want to tinker on. Dont sweat the costs. IF you do, and don't want to tinker on it, just buy a second modern bike maybe and mod it . Or a retro bike. 90% or 'done' cafe or modded bikes, TBH, are sketchy mechanically or electrically in some capacity, I've seen a LOT of really, really poorly done bikes that were pretty on the outside, by pros and hobbyists, regardless of how long they have been doing it, so be diligent on purchasing anything and asking questions.