For collectors focusing on console variations or accessories for their consoles, allow filter options to narrow down a user's focus on what kind of product they're searching for.

I just find myself going back and forth from Price Charting to gamefaqs frequently, if games could be linked to gamefaqs it would give allot of info about the game, ratings, reviews etc. https://gamefaqs.gamespot.com/

there are a few missing official controllers and accessories 

also themed controllers(super smash battle pads)

Show values for PSP UMD Videos: The Terminator, Bill & Ted's Excellent Adventure, Clerks, etc.

Add all the Player's Choice variants for Gamecube

When populating my collection, I will sometimes import titles from multiple sources, with certain titles naturally overlapping between the different sources. For instance, if I were to import from Sources A, B and C, and if Game X were present in all three imports, Game X would show up three times in my collection even if I would only own one copy of the game. With a large collection of titles and some titles being repeated more than once, scrolling through them can become a bit cumbersome.

Although there would be a few possible ways to address this issue, I figure the simplest would be to offer the ability to ignore repeated titles when performing new imports, or perhaps even to include multiple options for doing so (ignore title and platform repeats, ignore title only repeats, etc). Another possibility would be to offer a sort option that would only show one instance of each unique title rather than every instance of them, though I figure this type of solution would have little benefit in general use cases.

When listing the games on the console list screen, could there be an option to have the box art/cover art next to the name? Maybe different sizes too.

They are in that sweet spot of collecting right now where they are still easy to get hold of and cheap.

Can you add listings for individual Nintendo Switch JoyCon? (Left, right, etc) only prices for the pairs are listed.