Not "that" cheap. No diff locks.
My neighbor picked up a minty 450 for close enough that this price isn't a deal....but if he haggles, maybe.
I'll go look at it tomorrow since I'm up that way anyhow, and I'll post up.
It's been parked 6 months outside, so I'm guessing that motor is completely toast, and from what he described, it needs a new crank.
No quick headgasket job here. He's an auto mechanic, so any cheap fix would have already been done.