According to an article at http://gm-volt.com/2010/03/18/...44300/ the price for the Nissan Leaf will be between $38,600 and $44,300 before government rebates. I had previously heard from an inside source that the price would be around $29,000, but that may have been without the battery. Nissan has since announced they would not lease the battery separately from the car. So, if both of those reports are correct, the battery costs around $10,000 itself.
In any case, we should know what the official pricing will be in a month or so.