How about a zipp rear super 9 rear disc rim brake, used 4 times. $1200.

I've got a lightly used HED+ disc for sale, not exactly an AEOX, but hey, it's available!

HED Jet + Disc, maybe a few hundred miles over two years of TT racing. Skewer included, no cassette or tire. Will include unpadded Shimano wheel bag. Asking $725