players don't have contracts in BB. they can stay in your roster as long as you want them to stay. in real life, you raise salaries of an employee who is an outstanding performer to avoid someone else trying to attract them by offering a better pay. in BB this cannot happen. so the only point of voluntarily raising salaries of your own players is to throw money out the window.
So... dumb idea as no doubt its been suggested before.
Why not then make a contract system? Why not have things like a player will refuse to re-sign with you if he is unhappy with his play time, or the team's performance, his role, etc. As well as he wants a "fair market" value for what he does based on his TSP and his seasonal/career/both production...
Would make it more interesting. And gets rid of some of the training farm problems.