Meade Lexus of Southfield

I purchased a 2006 Lexus Sc 430, with a bumper to bumper warrant. After driving the vehicle for several months, I discovered that the right headlight would sometime go out. The vehicle was taken in for service and I was informed that it maybe a headlight or the computer. It was going to cost me $250.00 to replace the headlight. My discussion with the service rep, was what if it is the computer. Why would I pay $250 dollars for a headlight that I did not need. and why wasn't covered under the warrant. His answer wear and tear.