What kind of shape is it in?
The lowest I saw on eBay for a used unit straight from an individual was $150. Some other seller was trying to sell a Yamaha B-stock refurb for $300, which seemed too high based on other prices around the internet that ranged from $250 to $300.
So, I'd say in good shape, about $150 to $200, maybe $250. That's my thinking.
Adam