I agree with most players that a 10 year deal, especially when they are 39-41 is risky. But, based on past performance, the man has a legit shot to hit 755/762. While I don't expect him to be belting 40 a year when he's 40, I don't think 15-20 is out of the question (although Aaron, wasn't he hitting mid-30s towards the end of his career?). It's not like if he's chasing Aaron/Bonds, the stadium won't be packed.
Man has been the face of the team, and the face of the city, for 10 years now. I'd say 28M/yr, for 8 years. And I'd even make him part owner.
And yes, it's a shit ton of money. For what they make in one game, I'd gladly fist Jumbo's dog.