I think that he's a pearl and even 35m eur cash will be well worthy one day. But why pay that much if we can get him for less?
The question is if we can get him for less. The Chelseas, RMs, Citys and PSGs won't even look at him, most probably. He's not on the radar. They all want to please the fans with a marque signing and Jovetic isn't one. With last year's injury, Viola far from their sight and with him not doing miracles in Firenze, the foreign teams won't bother looking at him, even less paying +30m eur.
That leaves the Italian teams. Milan won't even try. Inter might but he might be too pricey. We might actually be the only ones after him and that automatically makes his price lower.
Viola won't like to sell cheap, but they can't ask for too much either, especially if Jo-Jo wants out.
Imo 20-25m eur will be his market price.