Walking to and from work is part of the best part of my day.
You could calculate how much it costs you to drive to and from work over a year here:
http://www.costtodrive.com/ This doesn't appear to factor in maintenance costs. According to AAA, driving a medium sedan 15,000 miles per year costs $9,641 (based on 2006 costs) plus you lease/loan payment.
Plus there are the added health benefits of walking more everyday. Difficult to quantify but definately worth something.
All and all it is a decision you would have to make and could be swayed based on whether the job was more interesting than your current job and if there are additional eductation/promotion benefits.