You think he'd bolt for less cash? No one will be able to pay him even as much as Portland. Maybe you're right, but that would make Stoudemire pretty unusual.
Joel's been a bargain for the Blazers. Although you could argue that he wasn't our starting center with the emergence of Oden, had Joel not been injured, he would almost certainly have opted out of his last year and gone looking for a bigger deal in the FA market.