For daily changes, the best way is to set a certain amount of free roster transactions. Something like 15 free transactions. Then any pickup after that costs $1. This keeps teams from taking advantage of daily transactions and picking up a pitcher for one start then dropping him. Plus you have a bonus pool of money to divide out any way you wish.
"I don't need your sympathy, man, I need my Johnson. ... What do you need that for Dude?"