It would be great to have a button on each wishlist item to move it to your collection. Right now, the only way to (indirectly) do this is by clicking on the wishlist item, then clicking "See Historic Prices" on the item page, then finally there's a button to add it to your collection. This would make updating your wishlist much more convenient and would also give that tiny endorphin rush from "completing" an item of your wishlist.

This would help a collector quickly track which games on their collection page are increasing or decreasing in value. Would be good to add to a sellers listing as well.

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.

Please add support for PAL PC games or add PEGI and 13 digit UPC support on NTSC PC games. Thanks!