you dont have expansion modules

It is a hassle, especially if you have many items, to know whether your listed prices are in line with others who might also be selling the same game(s). An example is Amazon's "Match lowest Price" option for sellers. It keeps prices in check while also helping to curb artificially inflating game values.

We need to be able to communicate directly through the website. The e-mail messaging system gets lost with the hundreds of other e-mails I recieve. Plus it'd be a lot easier to organize and go through the messages and whatnot

It would be useful to be able to view the marketplace through the mobile app. I would especially be interested in features similar to the eBay mobile app. Mainly ones, such as getting a notification on my phone when an item sells. This would allow me to potentially ship sold items more quickly.

Let me see only listings with actual photos of the item instead of stock photos.

Your pricing on some rare games makes no sense - for instance Bang-O NEW sealed copy is less than a loose price. Obviously this makes no sense and your system should recognize this. Don't use any price would be better - although I found examples offered on games on Amazon. This is a bad flaw, and really hurts the credability of your site.

Please add support for CGC half grades (0.5 increments) for comic books.  At least add 8.5.

The price difference of a half grade can be significant.

I mean u have NOK, our neighbor, why not add us :)

Please make it possible to add cases in stead of 6 loose boxes. Cases go for a premium.