i had one once 
i sold it after a couple years(varibright changed things for me… i also found i prefer a square canvas)… played 5 good gigs with it, though
those 512s are still amazing for things like ‘game of life’ and such… varibright’s not a necessary thing… but ya, i dunno about $7k+
(for that amount maybe buy a 3d printer and you can build 512 housings endlessly for others)
oh snapz, i see linked near bottom of that page with the 512, a nice varibright 256 from 2012, listed as “Monome256 MIDI Sequencer”… haha, i don’t think that person knew what they had. it’s also going for a nice price, too(i see it’s about to be snatched up). congrats to the new owner!