It is difficult to compare Brady and Manning's deals because Brady had two relatively "low-cost" years left on his prior contract. Manning was a free agent. Those existing "low-cost" years have to be factored into Brady's contract as they would bring down the "average per year" of the deal.
Look at it this way. You want to sell me a half-dozen roses. The market price for roses today is $3 each. So, if I walk in off the street (a free agent), you are going to charge me $18 for six roses.
But, let's say that you and I have an existing contract that calls for you to sell me two roses for $1.00 each. So, now you are only going to charge me $14 for the six roses: (four at the market price of $3 each and two at the previously negotiated $1 each).
I don't believe that Brady gave the Pats a "home-town" discount. Could he have gotten even more if he had played out his contract injury-free and hit free agency? Sure. A player almost always squeezes out the absolute biggest dollar going to a crappy team in free agency. But, that doesn't mean that Brady accepted a bargain-basement deal from the Pats. His contract was fair to both sides -- a win-win deal. He recognized the dollar value in shifting two-years of injury risk from his sore shoulder to the Patriots.
