I struggled with this one recently. My wife and I bought a 2 year old leaf (30 KWh) in Japan recently. We ended up with a pretty good deal -- the car only had 6K km on the dial and we're paying less than $300 per month with no down payment. I'm basically treating it as a lease. It was hard to find anyone here willing to lease a Leaf and I couldn't get them to give me an idea on the price without going into serious negotiations, so we went with the sale. It also helped that they gave us basically free charging for 2 years (they have a $20 per month unlimited charging plan, but then are giving us $20 per month in JCB gift certificates, which are accepted in enough places that it's essentially cash). My plan is to pay off the car in 5 years and replace it. I don't really expect to get anything substantial for it.
When we end up replacing it, I may consider doing a battery swap instead. The dealer told me that you can swap the battery for about $7K. I'm wondering if it will be possible to upgrade things for a reasonable cost in 5 years time. I've been looking at the new e+ leafs and I think the form factor for the batteries is the same, so potentially you just need to swap out the batteries and replace the power management unit. Whether that's even possible, I don't know.
Either way, if we can replace this car in 5 years with a car made 3 years from now, then I think we'll still be quite a bit ahead of the game compared to buying a new car.
I was a bit nervous about going EV, but it's been a couple of months now and I've had literally no problems at all. Now sure how well it would work in many places in NA, but here in Japan, I've been very surprised about how convenient it has been. Doing our first real road trip next month, though. We'll see how it goes ;-)