Without knowing the history of the bike, I'd say if it's a matter of your safety, play it safe and change the chain. (And sprockets too generally.) If nothing else, it'll bring you peace of mind. However, the chain could very well have been replaced during the previous owner's use, so it's hard to say whether you'll be wasting your money or not.
That said, how much mileage is there on the bike? I bought my '05 V-Strom with 23,500km on it, and wound up replacing the chain & sprockets at just over 30k. That's actually a bit early for many bikes, but the previous owner hadn't taken good care of the chain and the O-rings had degraded to the point of leaking the internal lubricant.