Bale's move from Tottenham Hotspur, which was worth £86m, has been widely criticised in Spain, with Barcelona coach Gerardo Martino stating that the figure demonstrated "a lack of respect for the world we live" in.
However, Carlos, who played for Madrid between 1996 and 2007, has claimed that Bale "deserves" to be valued as highly as he is.
"They have paid that because he deserves it. They also paid a lot for [Zinedine] Zidane, [Luis] Figo, Ronaldo, Cristiano [Ronaldo]. Barcelona also paid much for Neymar. They are worth it," Carlos told AS.
"That is why I don't understand Tata Martino's critique of the signing of Bale alluding to the economic situation. You have to pay for this type of player."
Bale's early Madrid career has been blighted by injury.