The Argentina international is being linked with a €100m-plus move to Barca this summer.
Laporta told Cadena SER: "He's a great player who, according to those who know much more than I do, would fit into Barça's system.
"He's not a player who would break the bank. First, he would have to show his willingness to come to Barça, which is what we want from all the players who might interest us, and it would have to be for a reasonable price.
"Then, it could be considered. But, given his current demands, they're out of line."
On the future of on-loan Manchester United attacker Marcus Rashford, Laporta added: "Rashford is having a good season in terms of goals and assists, we understand that he has been a good signing. Deco always tells me that he's a player who always needs a defender marking him closely and he can take one out.
"I think he's having a very good season, and we'll see what happens at the end of the season."