Arsenal and Dortmund have been linked with the 21-year-old in the winter transfer market.
Dybala is Palermo’s leading scorer this season with nine league goals while he has set up six others to help the Rosaneri climb to 10th in Serie A.
“Dybala is a world class player who is being compared to (Paris St Germain and former Palermo midfielder) Javier Pastore,” Zamparini told Italia.
“Hence, his price tag matches the skill: we are talking 40million euros and upwards.
“So far offers for him have only come in obliquely because they know how tough I can be (when negotiating).”
Dybala moved to Palermo in 2012 from home club Instituto and helped the Sicilian outfit gain promotion to Italy’s top flight in the 2013-14 campaign.
The South American is under contract with Palermo until June 2016.
Zamparini, meanwhile, expects Dybala’s compatriot Franco Vazquez to soon sign a contract extension with Palermo – his current deal expires this summer.
Vazquez and Dybala have formed a successful strike partnership in the past two seasons.
“Vazquez will certainly renew his contract,” Zamparini said. “But I would have preferred for it to be sorted out six months ago.”