"Vintage" from 1986.
I can't decide if I should laugh at the idea that this seller thinks a My Pet Monster doll is in any way worth 600 dollars. Or cry because my childhood is now considered "vintage". (I was 10 in 1986)
There's no way that thing is worth $600. Dudes out of their mind.
That's pricing for a run down Teddy Rockspin.