I'd buy it in a heartbeat at his asking price. Luckily, it is half a country away.
I happen to like the 600 gruppo, although some would pine for a Campy mix.
If this bike has no major issues, and if it fits, buy it. The price is on the low side, as I would pay more than that just for the frame.
This might help:
http://www.zullo-bike.com/contact-us.html Send them a pic from the ad and ask them about the frame material. The bikes were built from Columbus SL to Columbus Spirit, probably many flavors in-between as well.
Again, buy the bike.