I have about 1000 miles on this $200 bike
http://www.amazon.com/Stowabike-Folding-Suspension-Mountain-Shimano/dp/B006JCUPJY/ref=sr_1_2?ie=UTF8&qid=1367287036&sr=8-2&keywords=stowabike
It has a crystalyte 3525 and a backpack battery.
I removed the front derailleur and installed a disc brake on the rear. The steel frame is heavy but easily modified.
The suspension is adequate and appreciated for 20mph on city streets.
The relatively high weight of this bike isn't much of a problem storing it in my office or riding on the train. It's easy to put in the car too. It's a cinch to fold and lock up.
It has a short wheelbase and it's not that comfortable to ride, but it's great for city transport where you want something modest to leave at the curb.