I think if the price was based on a "Transfer Price Estimate" that would solve your concern. And for those who doesn't have it we could go for some kind of salary coefficient.
Again, I really don't get why free agents are not so "free". To me there is no correlation between their price and removing the excess or whatever. All I see is that trainers are overspending on a free agents out of pity or some other feeling. And on top of that their money just dissapear from the economy.