Paolo Berlusconi admits Silvio could drop the sale price for AC Milan if there are guarantees over squad investment.
Milan are in talks to sell to a Chinese group.
Paolo Berlusconi revealed: "If we decide to sell, it will only be to a group that will guarantee, not in words but in writing, a development of the club and the team, to return AC Milan to its former glory.
"Silvio also will give up a portion of the price, if it were intended to strengthen the team."
AC Milan's current price is between €720-750 million.