Every pistol there not on sale will be straight up MSRP. They will, from time-to-time, have sales and sometimes rebates on pistols.
They can also have sales and decent deals on ammunition.
Primarily, my wife and I purchase clothing from Gander Mountain as we don't have an REI or Cabelas and the Gander Mountain in our area has the best selection of Northface and Carharrt clothing. I wish they carried more from the 5.11 brand.
One thing the Gander Mountain in our area does poorly is stock women's clothing. Went in there looking for pants for my wife that were suitable for outdoor fall use. Every damn pair of pants they had in there were like yoga pants.
I also find their customer service there horrible. I'm sure that is different from store-to-store, but the people working there are not only unhelpful they're freaking rude as hell.