The 23-year-old Wales international has been linked with a move to Madrid following an impressive season that has seen him score 15 goals in 23 Premier League matches.
"I think he is a fantastic player," Calderon told talkSPORT. "He is one of those players you would always like to have in your team.
"It's true [Real Madrid] have spent a lot of money in the last three or four years but I think we are in a position to pay the money they are going to ask for.
"There is always a limit but Real Madrid is in a very healthy situation, economically speaking, so it would be in the position to sign him. I'm sure it will be a high amount of money because he is a fantastic player. A lot of clubs would like to have him."
Tottenham are currently third in the Premier League table.