In my hunts I often find myself at thrift stores, but I also spend a good chunk of my time sorting through indoor flea markets. Over the course of time, I've learned there are a few different types of flea markets. There are ones where all the vendors seem to have meetings, so they all have the same insanely over the top prices on video games. And there are the ones that have some seriously clueless vendors who either don't browse the other booths or just don't give a damn, which can be both good and bad.
With the first it seems like an idiot disease, spreading like wildfire from booth to booth. Everyone watches everyone and makes sure they don't undersell their products, possibly giving someone a good deal on their unwanted items. (GASP!) You can tell this type of flea market fairly easily as you'll notice more than one booth that has any spare video game cartridge thrown in among their doilies and trinkets. All of these games, no matter which booth, will be marked at generally the same price.
Locally there is a flea market with a handful of booths with NES games, all $5, but they're just tossed in among CDs, DVDs, Dolls, etc. I'm not saying SOME games aren't worth what these people are asking, but for argument's sake the fact is vintage games don't always equal CHA-CHING! The main problem is some games are highly sought after, so collectors will pay almost anything just to say they own one, which as a collector myself I can kind of see their point. This causes the untrained vendor to think they may be missing out on cash by not knowing what they have. To rectify this, they simply mark all their games at a set, and often times insane, price and hope they're not losing any money. The truth is the fact that true hunters, like myself, will NOT pay those prices unless the game is an absolute steal, even at the set price they're asking. Although rarely to never the case, I've honestly seen(!!!) the occasional person who has a childhood flashback right in the store and picks up the game simply based on that, paying no attention to the price tag.
On the flip side comes the clueless vendor, which as I said before is sometimes good and bad. This type is the type that I like, vendors playing against each other in an all out war of who will sell their games first. With these vendors who have games, one will generally be fairly reasonable, while 2 or 3 will be completely out of their minds, not taking a hint that the other booth has the exact same game for $2 and it hasn't sold in the 5 weeks it has been there.
Or for a real example, an Xbox. One booth wants a reasonable $50 for a fairly good looking Xbox with everything needed, as the other wants $180. This is the old, black Xbox and not an Xbox 360, most of which aren't even $100 used either. Or an Atari Flashback, one vendor wants $20(fair since it was CIB) and the other wants $75.
Simply clueless vendors can however be a good thing as they just want to make a little profit off the things they offer for sale. I enjoy flea markets quite a bit, because vendors will pack their booths with anything they think they can make a profit on. If they find it in their attic, closet, basement, etc. they will put it up for sale and just see if it goes. Often times I would love to make an offer for a lot of video games, but since the vendors setup their booth and leave, there is absolutely no haggling to be done with these people, so their products just sit there and take up space.
My principle is simple, I refuse to pay $5-10 for the one or two games that are worth it, simply because if I do the vender will see their stock moving and think that price must be ok! I would much rather take the chance and see if the vendor will lower the price just to get things moving. If I see a game for $3 or less, most of the time, if everything checks out, I will buy it. I found Casino Kid 2 for $2.50 at a flea market, originally priced at $5 the vendor was having a sale that day and just wanted to get rid of their games. Sadly, they moved out of that flea market before I could buy up all the games I wanted, but hopefully they'll return.
Almost every flea market I've been through has vintage video games, most of them are games I don't want to buy due to lack of interest or the price they're asking for them, and for one reason or another nobody else buys them either. If nothing else I've learned that even though there are more video games at the flea market than their are in the thrift stores, the vastly varying minds of each different vendor causes finding a deal to be just as much of a crap shoot as the thrift stores.