Not parent, if you want to sell an old original video game you know has value, it's either the proper collector channel (slow, super involved, higher pay), the generic resale channels (fast, no effort, lowest amount possible) or ebay (relatively fast, a bit involved but not too much, pay depends on how good you defined the product).

I had some old stuff around that Mr everyday might find (eg pristine original Gameboy Pokémon cartridge without box), and quick resale would give me 10 euro, involved resale would ask me hours and hours of work ebay allowed me to sale for 120+euro spending 1h on the description and picture (to show the scratch etc).

Another case is "oh you have the msi ge77vx4 laotop and you look for the plastic keyboard map in azerty? You can pay a 500e rma if they even allow it or buy the piece for 20e on ebay and fix it yourself"

Ymmv but it has a specific place that no one really have right now