A great feature would be the opportunity to purchase players from other teams who are "unhappy with current contract". Most of these players are on bot or inactive teams anyway, so it shouldn't affect many users. I would suggest that it provide the opportunity to purchase these players with 125-150% of their est. value or last transfer price (whichever is highest), combined with a doubling of salary. This would offer an opportunity to "salvage" decent players from sinking teams at reasonable prices.
While I'm on this topic, I also think there should not be a penalty for this attribute! It is a well known fact that players tend to play better when a contract is running out! Just look at Van Persie this season for a good example. Instead, when a player is "unhappy with their contract", their match performance should receive a significant bonus, maybe something almost equivalent to the effect on the individual player as a MotS now has, where the player plays at or near his maximum potential.
