Re: A strange question!
For less than a straight 4-stroke you can build a 66cc 2-stroke with a jackshaft kit so you have gears.
A good 3-speed hub bike works dandy, but if you need more gears you can use a derailer bike too.
On a 3-speed 2nd is like a direct drive, 1st is granny gear and 3rd is overdrive.
Just search this forum for "Jackshaft" for more info.
I have a topic about mine here too.