If you've not gone into many, it will take a little time to get your bearings, but you will find that most shops specialize in certain items and the other things are just taking up space. I like to find a place that specializes in hand and air tools. They will usually also have knives they have taken in, but aren't trying to make their retirement on. I've picked up mint 110's for as little as $10 in these places. They're just glad to turn them over.
While a place that specializes in firearms and knives may have a better selection, they usually want close to retail or sometimes more. Don't be afraid to negotiate. I get 25% off the sticker just by asking what they'll take for it. Also, when you go in, don't just go straight for the knife cabinet, stroll thru a couple of the aisles looking at stuff. You'll get an idea of whether the shop is marking their stuff way up or looking to move it.
I just bought a set of the game scene knives listed in Levines right after the Bicentinneal Custom. The set includes the 110,112,501,401,& 402 all with different game scenes deeply etched, and all in a wooden presentation box with a special Buck plaque on the cover. I've been looking at it for a couple of years, but the guy wanted $1000 and wouldn't come down. The shop changed hands a few months back and the new owner is interested in inventory moving. We struck a deal in about 2 minutes, and the set is now the centerpoint of my collection.
The point is, you never know what is waiting for you.
Good luck,
Doug
Lifetime member Buck Collector's Club