Jose Mourinho is a keen admirer of Pastore, who took Serie A by storm following his arrival from Huracan last year.
But even Madrid's millieu of cash and golden gooses won't have Zamparini flapping around.
"Have I received heavy offers? Real Madrid came along and they tabled a €25m bid, but I responded 'no' instantly," Zamparini told Il Giornale.
"I went to the player and told him everything. He is intelligent and he understood everything. It's better to be a starter at Palermo than a reserve at Madrid.
"In any case, for me today he is worth €50m (£42m)."
And despite Los Blancos' bid being considered tasteless, Zamparini revealed another reason behind the no-go Madrid deal.
"I think he will end up at Barcelona even though Mourinho wanted him at all costs. Pastore is a good friend of [Lionel] Messi and I know he made him a promise," he concluded.