I base my opinion on return on investment, the return here is exposure (I think most agree with that), and Contador while once unbeatable is now ranked where i rank him, and over time unless that changes his exposure will drop over time. At 4.5 million Riis won't be looking to drop him at all costs, but he must be having doubts. Just as BMC would with Evans at a rumoured 3+ million.
Lets take Evans for a second, from 2007 ranked 1,3,3,6,3 in the world, then 41 in 2012 ,and currently 37, for how long do you keep paying him and expecting him to ride like a superstar?
BTW I certainly wouldn't pay Wiggins, Uran, Kreuziger, Porte or Quintana what I'd pay Contador. I'd pay Froome more and it's debateable who'd I'd give more from Rodriguez, Valverde, Nibali and Contador.
Actually Valverde the least of that group, i find him boring