The Frenchman has voiced concern at football's "incomprehensible" transfer fees - including the 75 million-euro figure for which he joined Real Madrid in 2001
The Real Madrid assistant coach, who held the title of most expensive footballer on the planet when he moved from Juventus to Los Blancos in 2001, believes the 100 million-euro deal for the Wales international is simply one of many "incomprehensible" fees which clubs are willing to pay in the modern game.
"Ten years ago I was bought for 75 million euros and I said I was not worth this," the World Cup winner told Canal Plus.
"Even now I would think that a player is not worth this. It's football, unfortunately. It is incomprehensible to pay so much."
Despite holding reservations about the amount, Zidane is more than happy to have Bale at Santiago Bernabeu and the Frenchman is excited to have the opportunity to work with the former Tottenham star.
"My role will certainly be to explain that he has to play as he knows," Zidane continued.
"This is a player who has incredible potential, which he has demonstrated over the past three years and he is certainly among the top three players.
"But he can still progress a lot. I think he can bring a lot to Madrid."