Replace garage door or prime and paint?

The wood around my garage door and back French door are rotting, and I recently contracted with a well respected professional carpenter at my church to replace the rotting wood with something that resembles wood but is called PVC (I think). He charges $25.00 per hour plus materials. He also replaced a wood panel that was rotten on my garage door. I am in the process of priming and painting the garage door and some wood on the front of the house to improve the curb appeal. He says to prime and paint the PVC as well or it may turn yellow over time.

The cost of a new garage door would have been about $1000 which would not have included replacing the rotted wood frame.