Your comments

Our site does calculate a market price for video games.  We calculate it based on actual sales data.  A buyer and seller agree on that price and a transaction happens.  Yes prices have been going up, but that doesn't mean that isn't the market price.  If a buyer and seller agree that is the price then that is what they agreed.  

We do not include listing prices (just the price that someone wants for the item) because a buyer hasn't agreed to pay that yet.

Depends on how many people ask for it.  If only two people want it, then we probably can't justify the development to add that to the site.  Not worth the time or cost compared to other features that users want.  But if this turns out to be popular than we can add it sooner and it will happen.  Sorry I can't give a definitive answer.  That is why we have the request tool so I can prioritize these things.

Can you give me some examples of these figures?  Links to them so I can lookup more info.

We don't have a filter by what I'm missing feature, but you can look through a list by console and visually see which you don't have by looking at the orange vs blue buttons.

For example:

https://www.pricecharting.com/console/nes

You look at the orange vs blue colors on the right side for each NES item.  Blue means you don't have it, orange means you do.