The majority of things for sale outside of basic commodities are only valuable to a minority of people. If you have one copy of a game, you only need to find one buyer, so you either sit on it for a while until you find a buyer who meets your price, you lower your price for a quicker sale, or you never sell your item. The reason the going price for the item gets as high as it does because sellers are reliably finding buyers who meet their asking prices within whatever time window they consider reasonable for sitting on the item. Because of sites like eBay, everyone can see what these items are selling for, so the price for desirable items creeps up and not down. That's what I mean when I say it's an efficient market, and it's why people are asking $1,500 for copies of Shinrei Jusatsushi Taromaru and not Sonic 2 for the Game Gear. They're responding to what people are actually willing to pay. You can try talking them into selling it for less with this metaphysical argument of, "Hey, you know this item is totally worthless to the majority of people in the world, and like, what even is value, man?", but I don't think it's going to work, lol. Retro video games are a niche market. Nobody needs retro video games, and no one is entitled to someone else's retro video games. You had the opportunity to buy these games at retail price thirty years ago, same as everybody else did. The fact that you can still buy these games at all is because of "whalers" creating a market by continuing to sell these games second-hand. You're acting like they need to take a nationwide survey of what the value of the item should be in order to come up with a "well respected" price, when truthfully, the only people's whose opinions matter on this subject are the people actually putting down money for the item, however many or however few they may be, same as every other thing for sale.
Wanted to give an update. I sold my copy of Castlevania Bloodlines today for $50 on Facebook Marketplace (cause I didn’t want to deal with shipping). I hadn’t posted it for sale until the other day because other things have been going on and just couldn’t get around to it. Some might think that’s low but a couple of reason I only asked $50...I’ve seen a few on eBay around that price range, it’s missing the instructions and I live in a small town so wasn’t sure how many people would care about an original copy. I got 3 requests. The ones that are going for hundreds of dollars is completely absurd imo. There’s no way to justify that.
It's not particularly rare, but I think Girl's Garden tends to be pretty sought after by Sega nerds here in Japan, as it was Naka Yūji's first game with the company.
I landed a complete copy of S&K last year for only $40. There's only a tear on the bottom left corner of the box but otherwise it's in really good shape. I also got a copy of Keio Yugekitai for $70, only missing the instructions. It easily goes for twice that disc alone. As long as I'm patient (and check the new listings at cosmically right times) good deals can be acquired without giving in to what games usually go for. What I did give in to though was a copy of F-Zero GX for its average listing price and I feel it was absolutely worth it. Oh my gosh that game is amazing.