OK I'll address this from my perspective. I don't have a problem buying an old knife that is not in great shape to have it repaired.
I once bought a 1990 made red picked bone 110 that I could tell was an old painters work knife. The tip of the blade had been broken off and was rounded (I assume from opening cans of paint and such), it also had caulking/paint stuck in the picked bone handle. I sent that to Buck for a SPA and blade replacement. It was returned to me looking like a brand new knife. Win win for me.
Before

After
Another old Buck knife I saw in a junk drawer auction. I was looking at some junk drawer sales that had some military stuff and found one with what looked like an old one line Buck 110. I could tell by the look the knife looked like the spring had been replaced and not right. Maybe it could be fixed if the price was right. I asked a few of the knife hacks if they would change the spring and replace the wood with Sun Bleached Elk. I did get a qoute for the work just have not sent the knife for repair yet. See it below.
So if you want a project knife to have done, an old damaged knife may just be the ticket. I have also bought a few nice custom buck blades with no handles to be completed for less than the issued Buck custom would have cost.
Like this one