I'm not really bothered about mileage or conditions...without trying to sound too blunt. I am concerned that the plating is flaking from the teeth and small areas of corrosion are present. Scuff marks have started to appear on the teeth of my drive belt and my instinct tells me to act now before any serious belt damage occurs.
Mileage is important. A belt and pulleys should be good for 50-70k miles dependent on differing factors, for example have you removed your belt guards and riding conditions as mentioned. Without sounding blunt some of the offerings including the ‘exchange’ Custom Chrome ones on E-Bay don’t look any better than yours. If your instinct is telling you to change it you know what to do!