Zamparini brought Dybala to Italy in 2012 - signing the Argentine forward from Instituto - and he became a key figure at Palermo before earning himself a €40m move to Turin in 2015.
Dybala has received some criticism in recent weeks for his lack of goals, but Zamparini feels it is "crazy" to downplay the attacker's performances as he prepares to take on his former team in Serie A on Friday.
"Whoever criticises Messi is crazy. We are talking about the new Messi. He will become a player like Messi and he is already at that level," the Palermo supremo told Tuttosport.
"Ok, he does not score as much as last season, but he is always man of the match for Juventus whenever I see him play. He is the type of attacker who plays for the team and puts others in the position to score.
"I would say he is worth €140 or €150 million. Like I said, he is the new Messi. I have been saying that he is destined to become a star ever since he arrived at Palermo.
"I hope he will stay at Juventus. I think they can hold on to him. But of course there will be approaches. World-class players are always coveted by everyone. But I hope he will stay at Juventus for a long time."
Dybala has netted eight times in 24 appearances in all competitions this season.