Well I'm in San Diego County. There's a few stores, but only one of them (2 spots) called Luna Games has fair pricing. The one closest to me Game Adx seems to start the worst of the NES stuff like Top Gun at around $10 and then common good ones (Goonies) are in the $20s, so unless you want to go home poor don't. Game Rave down towards the central part of the county also does this price gouging like back when Earthbound was around $100~ on ebay the dude wanted $200 for the cart and FF2/3 were like $80 each, oh and the boring stuff most don't want still is like 10+ to start so they're pointless. Luna though starts stuff around $5 and goes slowly up from there and they do give good trade value. The flea market up where I'm in in the north area is hit and miss, more miss than hit quite a bit so in the last year but I had a good run of it in late June early July but it dried out again. But, central/south SD county has Kobeys, Santee, and Spring Valley flea markets and they do get good stuff, sometimes crazy good for low prices but I just don't drive it because a 100mi round trip kills the value in gas.
Los Angeles Co and Orange below that are your best bets. There's some crazy flea markets weekly, and I think it's one weekend a month the stadium the Rose Bowl plays at (Coliseum) gets an insane one setup. Also there are some really fantastic stores and one I know of is GameDude. They have just weird prices where something like a Mario is higher priced (since it's known a popular) but then stuff people pay deep for online due to being rare is notably less there probably just to move it.
