I always like when this subjet comes up...
Sog Tigershark (Carbon steel) and a Blackjack Rio-Grande bowie, both brand new with sheaths, $100 for both.
Sog Tech and Gerber MKII, both with sheaths, both brand new, $70 for both.
I got a Blackjack Effinghan skinner, stag handle, at a pawn shop for $35. It was used and not properly sharpened, I took it home and used progressively finer sandpaper and mousepad method, it is now the sharpest knife I own.
I got a Case long tail "C" tested xx copperhead, green bone, for a buck at a yard sale.
Gerber BMF with original intact sheath for $65.
There's more, but these are my favorite deals...so far.