For me, I'd never sell it and keep it in the trunk. It allows you to charge almost anywhere there is 120 VAC available in an emergency. Note that I've had to use it with an extension cord at the front of my house
after total shutdown of my Leaf about 100 yards from my house. No way I could push it up the driveway to my OpenEVSE 240 VAC controller. I just had to know how far I could "push" the Leaf (literally as it turned out).
A second time was going to my Son's house without the proper connector (miscommunication) and spending the night charging to get back! Just saying.....
Might find a used/new cable on ebay and buy the connectors needed - probably much cheaper if you feel comfortable with a little "assembly".
2012 Leaf SL; 43,000 miles. Battery replaced November 1st, 2016.