It the gun looks like this one:
Then it is an Ultimate Shadow, which is nice since they were once a top of the line model with CRF. Pay no attention to the buy it now price, as that is very unrealistic for this gun. NIB models are selling at a very discounted price on WSSM models (all calibers), as none of them are moving very well.
If one were to look a bit, a NIB model can be had for $400-500. Possibly a bit cheaper, although several guys are still trying to make money on them since the M70 boom since they closed the plant. This is a far cry from the $600-800 they were once selling for, but everything sold once the supply dried up (except the WSSMs, hence the heavily discounted prices).
A new Buckmaster 4.5-14 is around $270, with a few better deals here and there. One can find them used at around $225 with not much searching, and cheaper than that if you are willing to wait and look hard.
If it were me, I would probably figure since I could buy a new gun and used scope (and figuring new Leupold rings/mounts) for about $625-650 give or take, a used gun with used scope would probably be worth $500.
That's my .02 anyways...