After reading this ad, I would pass. I got a bad vibe from the seller's "if it turns into dust, it's not my fault" horse excrement. I don't do business with people like that if I can help it.
As for value - blahhh. It's not an awful deal, and I love 9sp record, but de rosa made much cooler 90s bikes. Also that size is hard to sell. I'd hold out for a primato. There is a decent chance it was made by Ugo, and I don't think it matters. I would trust quality. I personally like the stuff they did in the 90s with OS tubes more than the 80s bikes. I'd either want a pre80s de rosa or a later one personally.
All things considered, it's a nice bike, but it wouldn't be a must have for me and I think the seller seems like an ass. He has no other bike transactions that i see and combined with his "i guaranty nothing" attitude, I'd wait. A persistent issue with eBay is people with minimal knowledge and feedback expecting top dollar. For his asking price I want a knowledgable seller and a bike that's overhauled and ready to ride. I don't want "it's old and not my fault".