Tottenham boss Redknapp: Ba no freebie for Newcastle
He explained in The Sun: "As for Toon hitman Ba, you have to take your hat off to Newcastle for taking the plunge while others hesitated.
"But I am told the 'free transfer' came at quite a hefty price because of the fees people involved in the deal were demanding.
"Whatever was paid, Senegal star Ba has repaid it with his 14 goals in 17 Premier League games this term.
"He is making one of the hardest things in football look pretty easy right now."