My best score in this regard was probably twenty years ago now there was a small furniture manufacturer nearby where I got as much oak and lyptus wood as I could fit in my ranger for $200. Nothing over maybe 3’ long but I’ve gotten plenty of use from it. I also bought out the wood rack at an estate auction which had a few fun exotics in it for not too much. Neither of those holds a candle to this score though!
Actually my real best score was a bunch of maple burl off cuts my cousin had in the burn pile at an old lumber mill that I scrounged for free. That was “honey back up the suv, yes I know we’re at the beginning of a two week road trip we’re just going to have to work around as much of this as we can fit and still marginally have room for the luggage… you don’t mind holding the small suitcase on your lap do you” kind of situation. I regret not having had a bigger vehicle on that run lol.