HID sensor replacement ?

I have the dreaded red triangle light indicating the rear leveling sensor has gone bad on the HID headlights for a 2005. Have tried disconnecting the cable to the sensor and spraying it with contact cleaner and next step will be to remove and attempt to clean/rebuild it. If this still doesn't fix the problem, does anyone have a suggestion on where to obtain a new sensor at a discount? The Dealer quoted me a ridiculous price of $540 for a "new & improved" sensor since out of warranty. Judging from the number of posts on this problem, Toyota really should have done a TSB with free replacement as the original design appears flawed......thanks for any help.