What do you mean by older? What is the year of manufacture and how hard has it been used? Have you earned your money back on it? How often do you use it? Does it have any other problems? You might at least ask for some ball park estimates before deciding whether to replace or repair. I have the 200 - 400 f4 VR1 and it is an awesome lens. I bought mine in 2007. If something happened to the autofocus on mine, I'd repair it before I purchased another. It's always nice to have the latest model, but if its a business decision you have to ask if it's made its investment back.
