Feal 441 "Balanced" coilovers.
Bought this setup with 7k miles on it and never got around to installing it before I sold the NC.
$800 picked up in Phoenix or you pay actual shipping. The box is neither small nor light, however.
Manufacturer's URL:
https://fealsuspensionstore.com/feal-coilovers-05-15-mazda-miata-nc/
Photo of actual parts:

Bump! Someone needs these.
I don't need them, but I can certainly offer a free bump. 
Still available. I'd like to get them out of my garage.
Post-Christmas bump, these are still in my garage for some reason. Surely someone is driving an NC Miata and wants to improve the ride and handling.
Forgot about these. Make me an offer. I want to clear out the space.
What the hell, these are still in the garage. I keep forgetting about them and then finding them when I clean the shop.
$600. Someone come and get these, please. I'll put them on eBay in a couple weeks if there's no interest here.