I just took a ride around Maine and NH today and hit some gun shops. We started at the Kittery Trading Post, then went over to Hooksett to Riley's (excellent selection with good prices), then on to Milford Firearms (small, limited selection, higher prices, extremely friendly owner), then down to State Line Gun Shop in Mason (selection ranges from cap and ball revolvers to NFA with VG prices).
From my experience, stay away from Trader John's. The owner has always been less than helpful, but my last experience there pushed me over the edge. I got a call from my friend who wanted to go gun shopping to buy either a .444 or .45-70 Marlin. Trader John's was the first shop we stopped at.
My friend had a stack of $100 bills in his pocket and was buying that day. He saw a new Marlin 1895 on the shelf and asked to see it. The owner said "Why? You aren't going to buy anything today anyway." He pulled the stack of hundreds out of his pocket, and the owner got suddenly friendly, but it was too late. He thanked him for his time and said we were on our way to spend the money at Alstead. He bought a new 1895 Marlin there, for sell money, too.