I would say $50 +
it doesn't come up for sale often, it's in nice condition (better than mine! *cries*)
and wait - it lights up?!?!?!?! I've been missing out all this time!
I wish I could afford to upgrade mine....
all that being said, it's hard to price petite buildings because they don't come up often, the castle is hard to ship b/c it's big, and not everyone collectors petites (and if they do, they may not want buildings)....maybe make an interest thread to see who might want to negotiate price, or you can auction it