At this price point (i'm assuming this is your first or perhaps second "real" mountain bike) shop for your DEALER more than the bike.

If you are new(ish) to the sport you will have lots of questions and concerns and may need mechanical help down the road(errr trail )

After you narrow your search to 2 or 3 models that "feel" right, spend some time at the shop asking questions about service after the sale and find out how willing they are to swap parts(like saddles and tires and stems).

Go with the shop that treats you the best! A bike shop that treats you poorly or is overly snobby will certainly not be any better AFTER they have your hard-earned $$$ in hand.

Good luck.