What I find absurd about pawn shops are the customers who come in to a given store, find a given item, nitpick about why it is somehow not to their liking, and then make broad sweeping proclamations about the profession in general without really having a clue as to the complexity of the job. It sort of reminds me of the pimple-faced comic book experts wanting to argue with the author of a series about why a given super hero held his super weapon in the wrong hand in frame 6, page 15 of issue 62.
To run a pawn shop, you have to be the jack of all trade wares and general merchandise. You have to know high to low quality, multitudes of types, countless brands, sizes, attachments, and fittings. You have to know consumer trends (if you are good). You have to know your customer base and a huge percentage of your customer base thinks you are an idiot who paid nothing for the stuff for sale (sounds genius to me, but that isn't how it works) and who should sell it for just about nothing as well.
Pawn shops are heavily regulated in Texas, the location of the OP, subject to being audited by at least 4 different government agencies (-1 if you don't sell guns).
Suffice it to say, there isn't a broker alive who knows all values about all grades of all variants of all models of all types of product that may come through the front door. However, I will say this. Compared to most other industries, pawn shops are one of the most lucrative businesses around. You see a lot of banks, eateries, retails stores, etc. folding up shop, but not pawn shops. Contrary to the generalizations of the OP, people running pawn shops (not necessarily the clerks, but managers and owners) are some of the most diverse thinking people you will find who have to control a tremendous amount of variable information on a daily basis that changes on a daily basis. It is truly an amazing business.