I rode a scooter to work everyday last summer. I found a 1999 Yamaha Zuma on craigslist for $350. It needed work and I was able to talk the seller down to $300. I put about $150 into it over the course of the summer, increasing the top speed from about 5 mph (slow but running!) when I bought it to about 45 mph by the end of the summer. Despite having a poorly tuned carb and a giant exhaust leak I was still able to get about 60mpg out of the 50cc drivetrain (still needs CVT work and the exhaust fixed). My weekly commute cost about $3.
Scooters are a blast to ride, so what if you look a little stupid. If you do get one I would recommend a name brand like Honda or Yamaha for parts availability and quality. Also, as is said so often about motorcycles, its not the motorcycle you need to worry about its the other drivers on the road.
Scariest scootering moment yet: Driving down the road at night and a woman in a Mercedes pulled out of an apartment complex into my lane without even looking my way. I laid on my ridiculous sounding horn and she stopped in time for me to swerve around her, but its just another example of how alert you need to be when riding.
