My wife just came back from the dealership with an estimate: $667. Now I have to see if they'll replace it with one without homelink. There's no way anyone should pay to replace it, without any assurances that it won't happen again.
Please use this link to report the problem. If Toyota wants to be #1 - they've got to take responsibility for this hazard.
http://www-odi.nhtsa.dot.gov/ivoq/