Bought a Savage 220 slug gun.

Now I need to figure out which scope, was thinking of the Nikon Slug Hunter, guy behind the counter recommended the Leupold Ultimate Slam which I liked.

2-7x33
or
3-9x40


Could someone please blue book a gun value for me?
Benelli Black Eagle Slug 12ga., believe it's the black eagle and not super black eagle.