Prices of older used boats can vary 300% or more from bottom to top depending on condition. A boat that has been recently refit will be worth way more than NADA if it was done in a manner that appeals to you.
Look around you can buy lot of boat for the money. That would have to be one special Irwin at that price. Ask yourself if you had to sell what do you think you could get for it. If it's been on the market more then 6 months it's not priced right.