My STA-RITE Max-E-Pro P6E6D-205L just finished its 6th year of service. While it still seems to run well it is making a little more noise than it use to. I'm considering buying a replacement just to have on-hand. That way I will have time to shop price instead of having to run to the pool store. My question......can I just replace the motor on the pump or should I replace the entire unit? Complete unit is going to be around $400 and the motor around $200. All the websites seem to list the impeller on the same page with the motor and thats another $50. Anyone have any experience they would care to share?