Question 1: What sort of riding do you do? Do you spend most of your time in high gear? Do you mud in high gear?
If the answer to these questions is no..... then this machine needs to take a trip to the shop.
90% of the time belt damage is a result of rider error keeping the machine in high gear when it should be in low (hill climbing, deep mud, etc.)
The other 10% of the time is improper belt adjustment (free play) or improper alignment in the clutch/pulley system.
If you don't frequently smoke the belt, then something aint right.
If you do... buy extra belts and get used to replacing em frequently.