Bently, along with striker Roman Pavlyuchenko, is expected to leave Spurs when the transfer window opens in January,
However, Redknapp insists that the pair will not be sold cheaply just because of their desire's to leave the club.
"David would like to move, there is no doubt about that," Redknapp has said.
"He feels he needs to move on and play.
"Obviously Pav wants to move but we are not mad to sell them. They are not going cheap and are both good players.
"It is up to the chairman and whether he gets the money and it is the right offer. I would not let them go cheaper. Otherwise you end up giving them all away.
"I won't let my emotions get in the way of the fee we get for Pav and Bentley."