IMO, teams make those gambles all the time. Duncan on the Spurs was certainly one, Amare, even Nash with his bad bad on the Lakeshow. There's the insurance to recoup some of the money, plus teams now have more money to spend than ever.
What I would certainly hate is the Spurs getting into an Amare situation, where they could not insure him, because then they really would have a terrible time trading him and have to eat the whole contract.