Free market on wages would be very complicated to implement as I see it. How would it work?
I forgot to add that to my reply. I don't really know how. To have a free market, you would have to have the option for players to move freely, and to have someone negotiating on their behalf.
In HT, I suggested at one time that player salaries should be based on the transfer price. Currently, it is the other way around, where the high salary of a divine player reduces his transfer price, such that almost any team can afford a divine player for a few matches, but no team can really afford one for seasons on end.
This would at least have some sort of negotiation process, where a player's current team would be negotiating on his behalf (the more they get in transfer costs, the more the player receives in salary). But you would also have to have a mechanism where players are periodically exposed to the transfer market. There is also the question of how do you handle players who have improved their skills considerably in just a few seasons? You possibly could index salaries to player improvements - or simply give them X% more each season. If a player doesn't train, his salary would still increase.