Well, first of all - I think there´s two different discussions.
(1) IF there is a working formular, would the proposed system be desireable?
and
(2) Is it somehow possible to find such a formula?
About 1: If there would be any way to implement a seperation between buyer and seller, the benefit would easily outweigh the downside from my point of view.
About 2: I do think that based on the collected data over the seasons, the existing formulae which create salary, rating, efficiency and the information about how the skills and age and size affect each other when performing training (including the hidden skills) should provide such a heavy data base that it should be quite easy to find a correlation between those factors and the paid prices. The mathematical genious needed to program a working game engine (or overworking it) is probably alot bigger than whatever is needed to describe an existing process giving all the influencal insight the BBs have.
Just take a look at JosefKas work in deciphering many aspects of the GE - he had just a small amount of the overall data and still managed to set up models with pretty distinct and precise information about the outcome. Given, he was giving projections about mechanisms, not user behaviour, but the user behaviour is the very thing everybody wants to elminate when talking about fair prices.
By monitoring the "buying market", which would still be independet from the selling market, you also get a good feeling for changes in preferences, style, importance, so that any "market value" formular can hold a dynamic factor taking into account how "sexy" players are, for example - just as Wolph mentioned in another context - when beeing injured 3, 4, 5 weeks, rooks are highly interesting at the beginning of a season, lose value by the end, veterans gain value come playoff time, and so on.
Setting up such a system might be quite a workload, but with mathematical skill and a solid model it would probably be a huge step towards Buzzerbeater 2.0
Zwei Dinge sind unendlich, die Dummheit und das All...