I got a 2015 SV for with 21.5K miles for $11,900 in very good condition. It has 12 bars.
BARS - I would suggest you find one with 12 bars. Why accept less. They are out there for about the price you are paying.
YEAR - I also suggest you try and get the newest one you can afford (but I was not seeing a big difference between years with similar miles). In 2015 Nissan went to better battery chemistry, nicknamed the "Lizzard" battery. Again I suggest definitely get one with 12 bars. Of course LOW miles, good tires, good body, nice alloy rims is in the mix depending on your preferences.
SET YOUR NEEDS AND BUDGET - You need to research what you want and what you want to pay.
SPREAD YOUR SEARCH TO COUNTRY WIDE OR AT LEAST REGIONAL - I'd look country wide. Depending where you live you may have lots of local LEAF's to buy or none. I did an all Craigslist search and found my car in San Diago, 1800 miles away. Seems most EV's are on West Coast. If you live in California, you will have your pick. If the car is only 500-1000 miles away, rent a U-Haul Dolly trailer (front wheels off ground) and go pick up yourself (assuming you have a vehicle you can tow with). Where I live LEAF's are not common, therefore not a big local selection. Having it shipped is no big deal and easy, but that will add to the cost. I paid for the car Wednesday, Transport picked the car up on Thurs. I had car at my house Tuesday, late morning, before Lunch.
MODEL S, SV or SL. The SL is the delux with leather and all the bells and whistles. The SV has all the bells and whistles, especially in the later years, like hybrid heater, LED lights (which mine has). For me I wanted the SV and 12 bars. The 2015 was also high on my list for the Lizard battery, so that cut it down. "S" is a stripped down model. You can get 6.6KWh charger in a "S".
CHARGER - When I got my LEAF the fast charger was on my must have. However I have changed my opinion slightly. I was at first only charging at LEVEL 1 (because I did not have 220/240 LEVEL 2 charging cable). I went to LEVEL 2 16 AMP (3.8KWh, charging cable limited). It was a huge difference from LEVEL 1. I got another EVSE that is 20 AMPS, so I am charging at 4.8KWh and it is almost same time as 3.8KWh, a tad faster. The standard 3.3KWh normal charge (with LEVEL 2 cable) would have been sufficient for my needs, but I am glad I got the higher powered charger, even though I don't charge to the full 6.6KWh. On the "S" the 6.6KWh is an option. You need to research what years have what, what models have as standard and what is optional, (NAV, RIMS). I also have the DC Fast Charging standards – CHAdeMO charging jack. That is not for home use. I don't have access to a super fast charger, but it CHAdeMO can charge the car in something like 30 minutes. However there is some question to effect on battery life. As I understand it, OK for rare occasion but not routine charging. I doubt I will CHAdeMO charge my car.
When I was looking two months ago I found several 2015's for almost same or a little more then a 2013/2014. Also don't hesitate to buy out of state. You can always have it shipped to you. Cost of shipping? Depends on how far. I bought mine in San Diego, had it shipped ($800). If I were West of Mississippi or even Rocky's it would have been half that. I went with Pat, Drive Line Financial in San Diego. He is a LEAF expert. I also saw Carvana on-line selling many 2013 and 2014 LEAF "S" models, with similar miles or more than mine, for $12,000. I got mine about the same price but a SV. Carvana ships to you for free (but it is cooked into the price). The other ones I found on eBay. I found a nice one in Philly. It was a push between the two. The Philly one was almost in range for me to pick up, but at would be a 1600 mile round trip. The idea of having it delivered to me, not spending 3 days on the road, was better. I went with the California car despite paying the $800 transport fee.
I am a new LEAF owner (about 2 months) and not an expert, but understand where you are coming from as I just went though the decision making process. I know you want to stay away from 2011/2012. Again my advice is get 12 bars and the newest one you can find or afford. Also this is a good time as many 2015's are coming off lease and the new LEAF has new style and bigger battery.
To me I see no reason to buy one with 11 or 10 bars UNLESS THEY ARE GIVING IT AWAY. A new pack is $6,000. I would go for a "S" model with 11 bars only if it was $8,000 to $6,000. Keep in mind a new battery will be needed at some point. When? I don't know, but better to start with 12 not 11. I think (no facts just my opinion) once it is on it's way down, it is a steady decline from there. It also depends on ambient temperatures where you live and how you drive and charge. Hot rod driving (which is fun, fast off the line) creates battery heat. Have fun. I love my LEAF. I wanted to experience the EV for cheap. I looked at Tesla, and a used one was 4 times what I paid for this LEAF. It is only going to save me $6000 in the next 8 years, but then I will need to buy a battery pack. I suppose I am reducing pollution. I am only a few miles from free charging at a large park public. They have 10 covered charge stations, free. If I can figure a way to park there and leave to take care of errands, charging it for free that would be cool and save some real money! Ha ha