I'd guess that 300$ for a 94 XTR in any caliber is a good deal.
I use Conetrol mounts (on rifles), so, I know what they look like. Great mounts, but not cheap.
I'm kinda laughing about that S&W 460. I'm thinking it's for sale from the same syndrome I see at gun shows every time: really big bore firearms with less than 1 box of ammo fired through it. Those big cannons sound great on paper- and they're certainly effective in the hands of an experienced user. But, I think one bench session enlightens a lot of people.