I'm trying to collect the entire PS3 catalog and having the option to only see games I do not have in my collection would greatly increase the efficiency of searching.

Please add prices for Japanese Mega Drive games!! There are a lot of exclusives that didn't even get an European release...

Also, thanks for already adding Famicom and Super Famicom!!

Adding The cartridges for the Texas Instruments TI-99/4A would be nifty .Mattels Hyperscan would be a shortlist  but might be nice as well. 

The Commodore Amiga CD32 is a CD based videogame console of the 90s. 

Please add support for it.

Thanks!

Please add polish language and currency-PLN. Thank you.

There are a lot of manga volumes and box sets out there that are collectable and rare whose prices could be tracked.

I found a duplicate game of the same system (PS4) one with a long title and another with a short title.

"Mark McMorris Infinite Air" and "Infinite Air"

I did not find an easy way to report it, that's why I make this suggestion. Maybe adding a clickable button of "Report duplicate" at the side or bottom of the page or something.

Thank you very much

Having the ability to filter cards based on Ungraded price vs PSA 10 price would help those of us looking to buy raw cards on eBay that appear to be in mint condition (at least from the lousy potato phone pics) in hopes of getting those cards graded a PSA 10 for maximum profit or to hold for futures. There are several Pokémon cards that can be had Ungraded for under $15 and in a PSA 10 they go for $500+ depending on the card. Having the ability to see what cards could potentially 20x or 50x in value from their Ungraded price would be a rather unique feature.