SCREECHING AUDIO

Question

TWO DAYS OUT OF WARRANTY (IKNOW IT'S A COINCIDENCE) OUR TV MODEL #HDTV10A STARTED AN INTERMITTENT SCREECH/HISS SO LOUD IT SCARED THE B'JESUS OUT OF MY WIFE. I CALLED VIZIO AND THEY WANT $299.00 PARTS AND LABOR TO FIX THE PROBLEM. HOW CAN THEY KNOW IN ADVANCE HOW MUCH? ALSO: WE PAID $599.00 FOR THE TV SO IS IT REALISTIC TO BELIEVE THAT A REPAIR DIAGNOSED OVER THE PHONE WILL COST 1/2 AS MUCH AS I PAID FOR THE TV? ARE LOCAL REPAIR SHOPS ABLE TO REPAIR? ANY ADVICE WILL BE APPRECIATED. I'M IN THE OIO6O ZIP CODE.