Throttle Accutuator replacement only have 37,000 miles

[ladyday47]

I own a 05 Maxima with 37,000 miles. My car lost power while driving in 1st gear, went to 2nd would not go over 20mph, check engine light came on. Let sit over night drove home with no problems, but took to Dealer to check out engine light. Was told that I need to have the throttle accutuator replaced at $650 and also that it's not covered under my powertrain warranty. Am I getting screwed????? Thanks for any help!