It's a beauty and in great shape, I'd say that if the seller had it listed for a BIN of $400, it would be great but a starting bid of $400 might be too high. However, he doesn't mention NOS in the listing so that could work to your advantage as fewer people will see it.

I don't know too much about Casatis except that they are pretty highly regarded as being very well-built and beautiful bikes. They are not as big-name as Colnago or De Rosa but, again, that works in your favour. They are still in business today and have a larger market presence in Europe than in North America. I think most people would know Casati for their gold line model but that might just be me...