The deals for QB's go up and up every time someone signs a new deal, the formerly highest paid turns into the 4th highest paid, then the 8th, and so on. When you have a guy you think you can win with - you pay him. If it doesn't work out, you lick your wounds and walk away. You have to try and take your shot.

Teams that don't pay big money to QB's either have a guy on a first contract, or don't win much (see the Washington football team this year)