Alot. Ideally, Perkins and Rondo are the book ends between which you fill in the players for the next championship run.
The two most difficult positions to fill and arguably the most important for winning rings are the point and center; someone to man the paint and someone to run the show. In Perkins and Rondo we tow very feisty, physical, aggressive and talented youngsters at these positions and they really set a tone for this team.
This being said, you have to package Perkins with the right power forward for it to work. Perk is a plodding bruiser who plays some great D but doesn't score all that much. You need to put an athletic offensively minded PF next to him...like KG, for the mix to work.
But as others have correctly stated, I think Perk shines best when he is complimentary, rather than being the focal guy, the man.
I'd say $7.5 to $8.5 wouyld be just about fair. I think paying $10 mil plus would be too much. Seems like salaries like that should be from real impact guys like Ray, Pierce, Kobe, KG, Wade, Bron, etc.
I knwo there are other big men out there, I just don't if it's worth paying that kind of money+ for them unless they're Dwight Howard, etc. Though I also have to say Perkins plays Howard almost straight up... very tough call.
I'll conclude...If I didPay Perkins that much, I'd be looking for Rondo, Perkins and one other max contract player to be enough to take me to the promised land again. Would it be?