We picked up a used 2011 Leaf with ~30k miles for under $15k in very good shape. I live in Portland, OR, and it was a lease return from someone living in Vancouver, WA (found a business car stuck in the manual). I probably should have done more to find out the battery condition, but it has 12 bars at least.
Leases just aren't our thing. I figure that if i can get ~7 years and another 70k miles more, it will have paid for itself. It is mostly keeping the miles off my truck as a commuter car for ~15-40 miles a day. We put half down, and have $200/month payments for 3 years. A newer slightly longer range Leaf would have been nice, but I am very glad to have low payments. Even at $5500 for a fresh battery at ~100 k miles, getting another 100k miles for 9 cents a miles ($0.03 electricity plus $0.055 battery cost) is pretty darn awesome.
Most of the previous advise is very good. Know what you are getting into, it is like being stuck with a 3 gallon tank, but one that magically fills back up every night. Charging away from home is a pain, and look at where you would likely need to charge on the road for any frequent longer trips. The fast chargers along the Oregon coast are run by AeroVironment for example, which is a pretty lame system (must call for one-time use, and only has a $20/mo. plan). Until the DC quick chargers get more prevalent and the networks settle down, I suspect the vast majority of Leaf drivers are charging at home nearly exclusively.