I'll certainly never go through the expense or pain of building up an old gas-pipe Univega ever again I can tell you that much. I'm treating it as a learning experience though- and just about everything I'm putting on it can be transferred to a nicer bike once I have fun riding it for a few months. That gives me time to be patient and look for a higher end Miyata maybe (I really like those bikes for some reason).
So yeah, since this is a complete bike just make a low offer and don't worry if he says no- there are better bikes out there for that kind of money (depending on what kind of Univega it turns out to be)- and being in St. Pete and near Tampa means you'll have lots more opportunity- hell, "Squirrel Guy" may even have a better bike for sale.