@scissors
There's a secondary market for OWoD books, yes, but it's difficult unless you have direct buyers. I'd suggest eBay or WoD facebook groups. Hell, if you have some Revised VtM Clanbooks, there are a few I need...
Re: The Thread
For myself, I do buy the books I'm going to use, or if it's a publisher/genre that I'm going to buy more stuff from. I bought the MET Apocalypse book not expecting to actually have an Apocalypse LARP to play in, and I'm going to back MET Changeling as soon as it drops. Others, I might find a copy to look at and, if it's useful enough, I'll get it. I bought almost the complete run of Requiem 1e (skipped Carthians and Sanctified as I would never play those myself) and Lost when I was actively LARPing those, for example.