Would he instantly upgrade the team, absolutely. Would the Bills be a Superbowl Contender, even more so then the Pats. The problem is the Bills were reportedly 9.5 million under the cap before any draft pick signed. So figure the Bills have about 4-5 million left under the cap. Brees would probably demand somewhere between 20-22 million per year. Even after cutting Fitz they would still need an additional 10 to 12 million a year. So who else would be released Stevie, Jackson, Mario or Anderson?
If the price was right and if Brees's New Contract would not reek havoc on the Bills Salary Cap, I would make the trade in a heartbeat. His character, desire to win and his pregame huddle chants are incredible.
Unfortunately based on the overall costs between draft picks and salary cap, I would have to say no to trading for him.
P.S. Yes I want the Bills to win.