They were 22K a pair new. Used they go for around 13K.
Unless its an audio store going out of business, that's a pretty odd find. If they don't let you look inside the boxes and check the speakers out, I would bid very low. At the very least, the serial numbers are probably printed on the outside of the box. Call Revel and see if they know anything about the. If they turn up stolen, the speakers go back to the original owner and you probably won't get your money back.