For someone to give you an accurate price you need to give a little more detail, and a picture of the rifle.

The 788 was a very good rifle. It was also a very accurate rifle. I have never seen one in 7-08 however. But you see something new every day. From your description it sounds like the rifle has been used(but not necessarily abused). I would not doubt that the rifle could be worth up to $300 without the scope. Maybe more. Since the scope is a Leupold you can buy it with confidence. So the scope should be worth at least $150 or possibly more. Then there is the mounts. So $500 for the package is not out of line. Tom.