Is that your net price after tax savings? According to Nissan's website, that is the MSRP of the SL model after tax savings. The S should be closer to $21K. If that is BEFORE tax savings, then it looks fairly decent. If you haven't already done this little excercise, Nissan has this calculator that helps you figure out your total savings for driving the Leaf: http://www.nissanusa.com/leaf-electric- ... tor.button
As far as chains and snow tires, if you would use them for a normal gasoline powered car in your environmnet, then, yes, you will need them for the Leaf as well.
Disclaimer -- I have not purchased a Leaf, but I have researched the hell out of it.