The Welshman has struggled for fitness in the early stages of his career in the Spanish capital, but was selected from the start in El Clasico at the weekend.
"Did I play Bale for his price tag? For me, Bale is a player like any other. I think he was a good signing for Real Madrid," Ancelotti told reporters at a press conference.
"Bale played because in my opinion he could play and create problems for Barcelona, only for this.
"[Karim] Benzema did not start because I did not want the opposing defence to have a clear point of reference. So, Bale started on the left but could be repositioned with [Angel] Di Maria."
Madrid return to league action at home to Sevilla on Wednesday.