Well, we have started a thread for Tillman so I guess now they have to sign him.
4 years/$22M seems like a lot based on what they paid Kornet. Tillman is still only 25, so there is some potential ceiling there. He may well be worth an average of $5.5M per, and that may end up being what it takes to beat a taxpayer MLE offer, but I have my doubts that the Celtics will pay that much.
If everyone is healthy, Tillman is probably the 4th big in a rotation (behind Porzingis, Horford, Kornet), on a team that probably only plays 3 bigs on a regular basis and maybe only 2 bigs in the playoffs.
Now if you consider that Tillman beats out Kornet and is the 3rd big, that changes the rotation, but Kornet was the guy all season over Tillman and even in the playoffs (with Porzingis hurt) until Kornet got some injury. I am not sure that guy is worth $5M+ with the situation that the Celtics are in with the taxes and aprons.