He said: "The decision will be made by the coaches, but nothing is expensive or cheap on its own, before analysing what the counter-balance is from what you receive for the price you pay.
"Here (at Real Madrid), 75 million (euros) was paid six years ago for a 29-year-old player (Zinedine Zidane) and nobody questioned it. What I have always said is that this club want the money to be on the pitch and not in the bank, and it is (made) public that Madrid has it. They know what we earn, that doesn't mean the club are going to throw it away. We are not going to throw our money around.
"Last year we made signings which looked expensive, but now they look reasonable."
Calderon says he does not know how much Ronaldo would cost Real.
"I don't know. I am not aware of his contract. That is something between Cristiano and Manchester and I can't answer it," he said. And he added: "He is still not on the market, so I cannot say. We don't even know if he will come."
The Real president also looked to play down the recent row between Madrid and United.
"(Things like) occupation of countries and turning Columbus into a Spaniard have already been talked about," he said, in reference to quotes made by United number two Carlos Queiroz last week about Real's behaviour, when he accused the Spanish club of trying to 'nationalise' Ronaldo.
Calderon claims he does not know if the player wants to join Madrid.
"There is a good relationship (with Manchester United) and I have said that if someone decides to leave, it is very difficult to keep them. We don't know if Ronaldo wants to leave or not, that seems to me to be getting ahead of the events.
"If I talk about it, I will be criticised for having said there is a chance he will come. If it doesn't happen, it appears a failure," he said. "So much has been said that we don't know if it's true that he wants to leave.
"We don't know if he will say nothing or if he will say something different. If he says something different, Manchester will have to act and if they want to negotiate with Madrid or another club, they will do so. But they have already said they won't sell."
The Real president says he will not be to blame if the deal fails to go ahead.
"If he doesn't come, I won't consider myself guilty. What happened with Kaka (last year) was different. (Sporting director Pedja) Mijatovic had it (the deal) very advanced, also with Cesc (Fabregas), and it seemed a good idea to tell (people) what our project was.
"It didn't happen and I am sorry because they would have helped us a lot."
Calderon says the Ronaldo deal is now out of his hands.
"Right now, the Cristiano thing is beyond me," he said.
"For him to come, the player will have to say that he is leaving, then Manchester have to want to sell, we will have to play... there are many circumstances which must come together."
