Sounds like a pretty fair price to me. Don't put a lot of stock into the trail kit or the tow bar. Neither one is very useful. Honda/Kohler doesn't really make a difference, they are both generator motors. There are good and bad points to both engines. IIRC the frames that the Hondas were put into had jig alignment problems that lead to pins shearing in the driveline. Kohlers have a little jet in the top of the carb that gets plugged easily. I think both have govenors on them, there are tricks to disabling those though.
To learn more go hang out on Rokonworld.com to hear it from the guys that use them all the time.
I have 4 Rokons but they are all older 2-stroke models, my newest one is a '70. I've ridden with guys that have Kohlers and Hondas, they all were reliable, easy to start, quiet, and ran all day in one gear and on half a tank of gas.
All Rokons take a bit of tinkering to keep em in working condition, the technology built into them is pretty simple. I'd recommend riding one before you buy to make sure they are your thing.
Good Luck.
W-
