Edit: Oops, now I see you already did, good move! With such a new lens Canon has been known to be pretty reasonable with repair costs. Not always, but that's great news that it's nowhere near the other estimate.
If you can, consider getting the CPS Platinum service. It's 500 for the year, but your cost for repairs is reduced by 60%. That means if they quote you 1,000 dollars or more, you would save 600 dollars, thereby taking over the cost of the 500 dollar fee.
