I've never found had much luck with Thrift Stores (Especially Goodwill). Even Flea Markets I see EBay prices a lot.
And yes I have hit those Garage Sales where the seller wants stupid prices for old games.
I've heard a few times, But it's an old Nintendo/Atari/Sega these are worth a lot of money now. And I tell them NO it's not.
But they think I'm lying and I tell em, Good luck with that. lol
Biggest thing I'm seeing at garage sales are the Reseller Garage Sales. Where they have a sale every month and have full prices on games.
I just call it part of the hunt, everyone has their own idea what something is worth. If I see I good deal I buy it, if it's overpriced then walk away. There is one Thrift store I have found decent prices on games and I do check this store on occasion. But I don't even stop at Goodwill stores anymore.
I have your same luck. I live in the Bay Area. The flea markets are ebay prices. Goodwill, ebay prices, yard sales... You get the picture.
There are literally half a dozen retro stores here. One charges higher prices but has mint-near mint games in box, etc.
The other is like my unkept closet. A total cluster-mess but lots of gems in there, also high priced. Higher than amazon and ebay! One store though has nearly everything I am looking for in alphabetical order. Grouped by console. Play testable on the spot.
I actually have to set a limit before I walk into the store. I'll go in and say "I have x dollars". I'll pick out my selections clocking in at usually x dollars and change. Nearly every game is equal to or less than what they go for on amazon.
He rings me up. "Okay man, you still have x-30 dollars to spend."
When I look at him in disbelief he just smiles and says "you'll be back next month." And you know what. He's exactly right. As long as I have money to spend and a wish-list to check off, I'll be in that store.
I made the mistake of buying a genesis model 1 online online for $25 after shipping. I got it to replace one I have that has a quirky controller port. The ebay guy sent me a model 2. All my cables were incompatible. I went into my local store and talked to the guy about it. He said "man. I would have sold you an entire console with controller and hookups for the same price."
I asked if I could swap the model 2 console I had for a model 1.
He said "Sure, dude. But before you do know that the console they sent you has better quality composite and RF video. If you just need an AC adapter and a video cable you can have these for 6 bucks."
I bought the cables plugged in the model 2 I got on ebay and holy crap he was right.
I'm rambling now, but my point is there are still good folks out there that love the retro gaming scene as much as we do and they walk that line of having a healthy business but being a gamers game store.
This guy has my business for as long as he's in business!