I used to have a red 50cc '89 Honda Spree when I was 15 before i had my license. Didn't run when I bought it, paid 50 bucks and found the spark plug was caked and exhaust was plugged. After getting a new spark plug, it started and went about 15mph. After cleaning the exhaust out, 25mph. Finally cleaning / tuning, etc, 32mph. LOL I probably weighed 110 pounds at best then. Acceleration was not bad, but not good either. For the size of the engine, it's actually pretty amazing that it can even put out that much power.
I never really paid any attention to the gas mileage since gas was like $1.10 then, but I recall it being pretty good on gas. Suspension was great - compared to my minibike. I used to jump it, it seen it's abuse, it really held up. It was more of a toy than a means of transportation.. I would probably be reluctant to get another one though, but hey, why not?
Gas is almost 4.00 where you are?! I think I paid 3.099 the other day for regular unleaded..
Pete