There's absolutely no need to buy a used bike, when you can get a brand new bike, complete with a warranty.

Buying a used bike requires some knowledge concerning basic bicycle mechanics and structure. Otherwise, you're just gambling. You should also know what a bicycle should feel like when cycling comfortably. Therefore, locating the proper frame size and being properly fitted is most important, as well.

This one is a sure bet!
www.performancebike.com/bikes/Product_10052_10551_1130866_-1_400309__400309

Performance bike shops are located near many urban centers.

Find a Performance bike shop and actually test ride a bike, before making a purchase!