I have bought, traded and sold guns at the Mother of all Bass Pros in Springfield, Missouri. All my dealings were with the Fine Gun Room so I can't really comment on what goes on at the regular counter.
I never made the deal the first time I talked with them about a particular gun and I never paid close to the price marked on the gun. Several weeks usually passed before the deals were completed. Over the years I've probably bought or traded seven or eight guns from them and probably traded them five or six guns including a little double rifle I wish I'd kept......not that I didn't get what it was worth in the deal.
I've never regreted one of those transactions. Hey, I once bought a pretty nice Purdey at a pretty nice price from Johnnie's boys. I thought they were all fair. They took some time and discussion and getting to know (and maybe help educate a few) them and their guns. I also gained some knowledge from them. Some of the guns I would like to have bought I didn't because we could never agree on what the worth was.
If you are looking to swoop in on a fantastic deal, these places probably aren't for you. If you are easily offended by what is marked on the price tag.....probably not for you either. If you are willing to drop by frequently, stay a while and visit, get to know the people and gently work the deal, you can come out fine on some selected guns. You may even get a few unsolicited calls on some unbelievable deals.......like a neat, excellent condition leg-o mutton case for $20.......hey, stranger things have happened.