Hi Joanne, I doubt I'm much help. I know little about the Leaf. For an electric car purchase (even though I don't like stealerships much) I'd take it to a Nissan Dealership and pay to have them give it an inspection. One specific to electric cars where they can test the battery in different ways. The price is very competitive, but the description is pretty limited. I'd wonder if there are issues that aren't being reported. The seller's listing offers a free carfax and I'd take them up on that in addition to having a factory dealership run an inspection.
Best of luck and know that you have a cool username. Welcome to NICO Club!