For $250, a gas powered bike is his only option. Electric bikes have advantages, but they come at over twice the cost.
From what I've seen and read, there aren't many (if any) fully assembled gas bikes. I doubt if any would come in that price range. Mounting a 2-smoker is frequently not an easy DIY. Also, keeping one of those things running sometimes requires having a full-time mechanic on retainer. Unless he gets lucky on Craigslist, I don't know of any simple turn-key motorized bikes (e- or gas) that meet his criteria - jd
