I think I may up my limit to $300. Besides lightweight, upright seating position (curved handlebars?), and easy to pedal; I would also like a lever to quickly release the wheel for easy car transport. Would I be able to find something decent with those features in my price range? For riding on the street and sidewalk, does the width or type of wheel make a difference? Example mountain bike tires vs 700cc or whatever those really skinny tires are called.