It has a FOX COA, so I think it's the real deal(I'm pretty sure FOX wouldn't lie, unless they want to lose viewers). The COA says that it's screen used(which hopefully means that it was SEEN on screen, not that it was just used on a set) during Season 5. The seller believes it was used in Crush(see picture) right before Buffy discovered creepy Spike's shrine.
Come on, it was about an inch from Sarah's foot. Buy it!