The former Tottenham manager launched a scathing attack on some of the players he inherited from Mark Hughes and hinted that he intends to sell Jose Bosingwa in January.
Redknapp suffered his first defeat as Rangers boss with their defeat at St James' Park.
Asked about his plans for the January transfer window, Redknapp said: "I don't want to spend their (the club's) money, to be honest with you.
"There are a lot of players at this club who earn far too much money for what they are; far, far, far too much money for their ability and what they give to the club.
"I don't really want to see the owners have their pants taken down like they have in the past. There's a lot of agents made money out of them.
"I fined a player last week and he was earning more than any player earned at Tottenham.
"You shouldn't be paying massive wages when you've got a stadium that holds 18,000 people.
"This club (Newcastle) holds 52,000 and most of their players will be nowhere near some of the wages some of the players are earning here."
Redknapp also confirmed that full-back Bosingwa had been fined a fortnight's wages after refusing to sit on the bench for last weekend's 2-1 victory over Fulham.
He said: "He didn't want to be on the bench and didn't want to be a substitute, so he went home.
"He has been fined two weeks' wages, £130,000. Not too bad for two weeks, decent isn't it? Not too bad for playing on a Saturday, it's okay."
Asked how he might handle a player like that, Redknapp said: "We'll find out in January."
Redknapp played down the likelihood of signing Newcastle striker Demba Ba, who has a £7m-release clause in his United contract.
Redknapp said: "We've not got £7m to spend on a player, I'd have thought."