I am in the process of building a CB750 cafe. This is a barn bike that I paid $400 for with out title and it had not been run for 4 plus years. Was this a crap shoot yes. Before doing anything I did the whole VIN thing to make sure it wasn't hot. Did that before the purchase. That was free.
It was missing major parts such as seat, headlight and exhaust. had the tank, sidecovers in questionable condition. I put about a $100 bucks into getting it running and had it running in 6 hours, plus/minus. I have not done a frame off but I have gone through most everything but the motor. Bought some stuff that it needed and stuff I wanted. It is ready for the street except for paint and I should be done with that in 3 to 4 weeks depending on work travel.
My point here is that I have not been extravagant. I am making the bike safe and fun to ride and look at. I have kept a spreadsheet of my spend on this project and to this point including the cost of the bike I got about $2300 into it. It is not that one thing cost a lot but there are many things that cost a little. My two most expensive things were a seat and muffler. That equaled the cost of the bike. So it adds up quick.
So right now I most likely would be hard pressed to recapture my money out lay on this. Oh I now have title as well something less than $50 through the state of Colorado. The clean title will add another $500 bucks.