I used to work with several of the local pawnshops, repairing and upgrading the computers they took in pawn, training their staff, and helping them set the prices. I became friends with many of the owners and spent countless hours "behind the scenes". During this period I learned quite a bit about the pawn business. I have also been buying, selling, appraising, and auctioning ethnic and cultural art and antiques for the last 17 years. Here are a couple things have learned.
Pawn shops don't make their money buying and selling stuff. They make their money on juice. Juice is the interest paid on the loans people receive when they pawn something. Pawnshops will generally payout twice as much on a loan/pawn then they will on a straight buy because the more they loan, the more juice, and the more likely they will end up owning it after the customer has paid more in juice than the item is worth. Juice is the number one source of revenue for a pawnshop.
A $1,000 ring would get you $200 at the average pawnshop if you are looking to sell it, but they will loan you up to $500. Your payment will be $100 a month, which does not go to redeeming the item. After 5 months, the pawnshop doubles their money and most customers will abandon their item.
Most of the gold jewelry is sold as melt, not as jewelry. They send batches every month or two to be melted down and sold. The larger stones are sold, the rest end up in a box in the safe that just accumulates over the years. This is the second largest revenue source for a pawnshop.
Most of the customers walking into a pawnshop are there because they face eviction or utility cutoff. Not to feed drug habits. Just normal folks that fell on hard times and need money today to buy food, pay rent, or to keep the light on for another month.
As for the auction values stated in these shows, they are not talking about Ebay. The auction value they are referring to are specialized Civil War, or Toy, or other collectible specific auctions that are held by top auction houses such as Sothebys. These specialized auctions are few and far between. They are also very selective as to what they will and will not accept. They also charge 20% or more as well as large fees if your item does not sell. Therefore, these values are almost never obtained by any individual or the pawnshops and pickers.