to get a shotgun drilled and tapped for a scope rail? Not an issue on my 935, but thinking about my son's Remmy 20.
10 bucks a hole plus the base around here.
Your area may vary.
Paid 8 bucks a hole plus 5 for the base
went to 3 local shops and got quoted 55, 75, and 40 for four holes and weaver rail.. went with the $40 price and had it in two and half weeks, did a great job and love my fast fire II on it