I'd only see this applying to the automated market we have since its otherwise impossible to determine if something was sold or not (or the amount it was sold for) just based on transaction histories.
Someone made a similar suggestion to yours before, but I'd also like to see infographics or at least [averaged] statistics on items and how they were used in transactions.
This would make appraisals a lot easier (lessening the need for the price check megathread), but there would still be a number of factors to consider (such as daily sales and how they affect the appraisals, restocks, etc).