Create a tool for users to create a custom set or list.  Then let users collect against that list and see what they have in their collection and what they don't have yet.

Examples: a list of all licensed NES games, Mega Man home console games, games published by Konami, etc.

The site doesn't currently track or list Bandai WonderSwan consoles or games. It could be great to have them!

Keep track of prices on the Starlink toys

I'm so happy you guys added Famicon! It would be amazing if you continued with more imports especially the PC Engine it has such a huge library of games its hard to know what a fair price is. Thanks!

I pulled a German SIR card and I would like to track the value on this site aswell. When adding this feature, gradings like from AOG could be added to the site aswell. The german market isn´t that small due to 3 german speaking countries which print german cards.
By adding this feature it is ensured that people in germany can track their whole collection. (because most people buy english/japense/ or german only)

Btw. The German SIR goes around for 290-500€ and the same card in english for 240r€

Add One Piece Japanese TCG 

I think Mercari should be used to check prices against in the market as they are becoming a heavy hitter for resale.