There's one on ebay atm but he never gonna get that price for it (it's a useless expired devkit)... buy now for 999£, for that price you can find probably 3... and yh like DROIDBOT said, last one was last month for 400£ in NEW CONDITION on ebay...
Without the proper software included on the devkit and on cd to install on pc & with a unexpired license + account to access devnet, they're pretty much as useless as a paperweight... There's 2 types of ppl that may buy it... a collector like myself or a hacker who wants to reverse engineer it to build the next jailbreak for ps4 and potentially ruining the system for everyone.
But like i said before, if you really consider to sell them i'm interested & for the right price i'll even take both.