I'm looking for a used bicycle for the upcoming school year. I'm hoping to spend between $50 to $150, and would also be interested in buying a lock and/or lights. I'm 5'1, so I'd need a bike for that height - I just need something to get around campus. I will not be in the Bay Area until Sept. 18 and I can pick it up anytime before Sept. 20. Help a broke freshman become mobile!