Retro sperg here.
The retro game market is fucking insane. Some of these prices aren't entirely without merit. For example, Sega Saturn stuff, particularly the games made in 98' like Shining Force III, Burning Rangers, and Panzer Dragon Saga when the print runs were basically nothing because they didn't have the money. Then there are just some games where it's obvious what's going on if you're the least bit familiar, like the money laundering shit in HA, Solatorobo/Tail Concerto/Klonoa where furries hoard the entire supply, or any first party Pokemon game where despite being the best sellers on every console end up being retarded because everyone's buying one of each because they have a collection fetish, I'm buying up the shit i can now before it gets any worse(god only knows when the shit's gonna crash, i sold my shit off years ago anticipating at least SOME of it to go the way Atari 2600 had, but 14 years later and it never fucking did and doesn't seem like it's going to stop any time soon.), but frankly, if you're new i wouldn't recommend anything harder than checking your local pawn shop, it's gotten so bad that even the ones that check ebay tend to slip up and sell these things for much cheaper.
Thankfully, there's many, many options around this, from emulation to flash carts to replacements to the disc laser that run games from SD. You'll never need to touch a game cart if you don't have to.
The fact that so many GBA carts are expensive now is mind blowing to me, I would have guessed so many would have been cranked out that they would all be cheap, but no.
For the longest time, GBA games were basically worth nothing, i always thought that was because of the rampant amount of bootlegs flooding the market, but i guess not. Even the genuinely rare games(anything ATLUS published) were all, at worst, slightly worse than original retail.
