No one should be giving answers to this question without knowing how much a max deal is for a player with Rondo's years of service! Abstractions just confuse the discussion.
Rondo will have 9 years of service when his contract ends. That means the max for him is 30% of the cap. SO if the cap were to be $60m, the max for him would be $18m for the initial year plus raises each following year.
So there you go. Is Rondo worth $18m the first year of the new contract and even more each year after?