This is what I do as well. He may be a little more willing to do this if you buy that 7PRC from him. May even save you a few bucks compared to Sportsman's.Here's an idea that may cost you a few bucks but makes your life much easier:
I had a few firearms that I wanted to sell. I didn't want the hassle of posting the guns and dealing with all the perspective buyers and their FFLs for shipment.
I took the guns to my local dealer who I've known for years. I asked him to post them to a national gun auction site. He told me that he would want 20% of the sale price. All the guns sold and some sold at prices that surprised both of us. The site got a few % and my dealer got his 20%. For his 20%, he did all the posting, dealt with all the buyers, boxed all the firearms, shipped everything and took care of all the paperwork. It was the best money I ever spent.
I have since brought other firearms to him for resale. Things went smooth and I was very happy with my decision to go this route.