I purchased a Taurus 689, blued, with a 4" barrel from a pawn shop in VA about 15 years ago when I lived in Fairfax. I got a very good price on it, it was in nearly-new condition, and it functioned flawlessly for the 8+ years I owned it. I later sold it for a slight profit (still kicking myself for letting that one go!), because I'd taken very good care of it, put better grips on it, and had a gunsmith do a REALLY smooth trigger job on it.
But these days, it seems that most of the pawn shops are charging near-retail for used guns. I've been looking for a snubbie S&W revolver and a "black rifle" in .308 or .223, and most of the ones I find are as within 10% or 15% of the price of buying new.
Back in the day (like in the 1980's) there were a LOT of bargains to be had on firearms in pawn shops, but these days, used firearms in good condition seem to have become a commodity, and aren't discounted much at all.
The funny thing is, if you go to SELL a gun at a pawn shop, they give you the same amount of money they would have given you in the '80's (which is always low-end Blue Book value, usually less than 50% new retail if it's in very good condition). But then they'll turn around and sell it for retail or sometimes more (especially if it's a "black rifle" or a particularly "popular" pistol like a Glock or a KelTek)