That's been what 6-8 years ago? I'd call it a belt that lasted pretty well. Having also been bigger at a time (about 50 lbs) I know that most times belts are worn tighter, the bigger you are so that contributes to the cracking around the adjustment holes. Not to mention the twist a belt sees as it hugs handles and a gut. (no offense intended, just pointing out the things that accelerate wear)
6-8 years of daily wear equates to about $0.03/day. I'd call it money well spent and buy a new one in the correct size.