Hi, I have a well maintained 2000 Honda Accord with 247k miles working flawlessly. My next scheduled maintenance is the Timing Belt / Water Pump. Since I already have all the related parts, I contacted to my mechanic to schedule an appointment. He recommended changing the oil pump the same day due to the high millage on the original part. The part cost about $200.00. Is this a good idea due to the high mileage or not really necessary? Thanks!