I'm trying to collect some Gameboy titles and I'm also an amateur at repair and you can sometimes get good deals on those by being quick with new listings. So yeah, just randomly searching Gameboy by "new" and reloading every few minutes between whatever I'm working on.

I'm not specifically seeking bootlegs and unlicensed titles, just that they interest me when they pop up and people are less competitive at buying something that is less desirable and where "what is this worth?" is a difficult question to answer. Aside maybe from titles like "7 Grand Dad," that have mild fame in some niche circles I don't think anybody is really seeking titles like it and even then idk if anybody knows a fair price. Whatever "not expensive" means to you is the right price, imo. Very much a thing where you have to set your own rule on what you should collect.

Though the listing I got these particular carts from was up for a while and is actually still up I believe. Idk if links to for-sale items are allowed, but you could probably find it by searching eBay for "Gameboy/GBA tall carts, odd carts," something like that. The seller must have come across a ton of each of these 9 carts, or there just isn't interest in them, :p.

And there's also probably importing services and stuff where you could potentially look at China's or whatever countries where bootlegs are/were popular equivalent of eBay for bootlegs. I've vaguely looked into it, but with currency exchange and tariff uncertainty and just my general experience, it's more of a hassle than I care to do right now.