Both players are impressing on-loan at Bari this season.
"I paid 5m for Ranocchia two years ago when he played in Serie C. Now he plays for Italy," said Preziosi.
"Andrea is a defender worthy of a big club."
Asked if there had been any interest in the 21-year-old who is currently recovering from a serious knee injury, Preziosi said: "Yes, Juventus wanted a valuation. He is forging ahead in his recovery and should be back soon."
Bonucci is part-owned by Inter, although the player is said to favour a move elsewhere after rarely being given a chance at San Siro.
"Juventus are interested, but it's normal. After Nesta and Ranocchia, he is the best around. But we are not a super market. We don't have to sell," Preziosi concluded.