Most reality shows are quite scripted and prepared. They might not write the actual words but situations are set up and contrived to look good and be funny, entertaining etc. Don't take them as truly slice of life moments.
Well, i don't mean if it's set up, but more like: if you have some object you want to sell, you instantly think about a pawn shop (and not some second hand website?), are there really people who buy this stuff in a pawn shop?
I bought a couple of Christmas presents in a pawn shop this year. Pawn shops (at least in Minnesota) are not very inexpensive. Generally a place people go to get fast money for tools, musical instruments, & jewelry. If I go into one (not very often) I may buy used DVD's, or video games.
If you need money you can take an item ti s ok pawn shop like jewelry or s TV or something with some value and either sell it usually for a lot lower than market value or borrow against it add collateral. If you don't pay the loan back the pawn shop then sells it and keeps the money.
People usually only use pawn shops to sell or trade something if they are desperate for cash or are trying to fence stolen goods, since they are not a very good deal - generally someone selling to a pawn shop will only get a fraction of the price. It's a much better idea to sell something via Craigslist or eBay, or to sell it through a reliable reseller. It is regular business, but not wise business.
Pawn shops have also been around for over 100 years, well before the Internet. As mentioned above, most people tend to use them as a last resort for immediate cash and don't have time to sell them. That being said you will not get anywhere near the price it is worth. A $3000 piece of jewelry might only get you $100-$200 dollars.