Definately worth a look- mine was on ebay- we negotiated a 'buy it now price' we were both happy with. Was great over the winter!
Sometimes paying cash gets you a bit of a discount- wave the 'wad' under his nose! for this amount of money I would also want to look at the goods and meet the guy- you can usually tell if people are genuine when you meet them face to face.
IMO if the top is in the condition advertised the price would be about right.