Despite this, I don't think it's really that ridiculous, the club could make a big step in the following season. Di Natale hasn't denied his retirement, Napoli selling Lavezzi. They can probably spend more than Lazio and Inter, and be the second highest spenders in the league this summer. Aside from not being Luis Enrique, Zeman will be a benefit for their younger attacking players like Lamela, Borini, Pjanić perhaps Bojan who all have potential. If they prove they know what a competent defender looks like, I wouldn't be surprised to see them quite high.
Edit: Lazio have a pretty good squad actually, lets see what Petković does.
So they'll get €40M, plus I'm sure Berlusconi could pop another €20/30M from his own pockets. That money could be used to build a very strong squad, not dependent on 1 player.