The 24-year-old moved to Real from Tottenham earlier this month for e100million (£85.3m) after negotiations that lasted the entire summer transfer window.
Bale scored on his debut against Villarreal but missed a Primera Division game against Getafe at the weekend due to injury.
However, Perez insists the club did not pay too much for Bale and told Cadena SER radio that he was content with the fee paid.
“Bale has come cheaply. Signing the best players out there is Madrid’s philosophy and Bale was the best available player this summer. We had been following him for two years,” explained Perez.
“Tottenham did not want to sell. We learned that Manchester United had made an offer and we made one ourselves.”
Key to Bale’s switch to Madrid was the fact he would be fulfilling his boyhood dream, Perez saying: “Since childhood he had had the dream of playing for Real Madrid and he asked us to make it possible for him to come.”