At that weight, I won't even think about buying one.
Honda built a XL200R (factory legal dual sport) in the early eighties that wieghed less than 260lbs. I had one and while it lacked the power, suspension and brakes of new bikes, it was light enough that I really could go just about anywhere on it, even if that meant physicaly lifting it over a log or large rock.
The light weight of that fully factory legal XL200R is what made it attractive. Anything with that small of an engine should never come close to 300lbs. It was kick start only, but it had a 12v charging system and a battery.
For thousands of years, riders were satisifed with one horsepower and they traveled the world.