For a mid to late seventies celeste green Bianchi with full Campy Nouvo Record group suggests, to me, that the asking price is not out of line. Value does depend on many things, of course, and knowing where the bike is located would add to or detract from the estimated value.

Anyway, were I in the market for such a bicycle, I would not be uncomfortable with paying the price or, better yet, just close to is. By the way, look at the top of the rear derailleur for two digits. Those will indicate the year the derailleur was made and, probably, the vintage of the bicycle, also. You can double check by removing hub lock nut and looking at the two digit number there, just for confirmation.

Hope that is a help.