No offence but I would hardly call that brilliant. What he does is he explains the situation Barca were caught in very well.
But to try to justify Ibra's price by saying you saved on Eto'o is conveniently forgetting how good a player Eto'o was for you guys.
If Messi was caught in the same position for example he would have been given a raise no questions asked regardless of how much it cost.

He values the loss of Eto'o to a free transfer at 20-30 ME.
So how can it be said that Ibra's effective cost is only 40ME when, even if you save 20ME + 10ME in wages and signing bonuses if Eto'o's contract was renewed, you're effectively losing a 20-30ME striker?
It's simple math really. You're still effectively paying at minimum 59ME for Ibra. Is he worth that much? That's not for me to say.