Money is tight at the Reebok Stadium and Allardyce wants enough cash to bring in a quality replacement should Stelios move on.
"It will come down to how much City offer him, how much we offer him and how much City offer for his transfer," Allardyce revealed.
"If he stays, that's great. If he doesn't, he goes on our terms - not on anybody else's. We'll see if City want to negotiate.
"If we can get £4m, we've got some money to spend."
Meanwhile, former Bolton defender Mark Fish has retired from football after many years in the game.
Also, current right back Nicky Hunt won his eighth cap for England Under 21's on Tuesday playing the full 90 minutes.