Chairman Peter Pannu insists Birmingham will not sell any of their leading players on the cheap following relegation from the Barclays Premier League.
Blues are facing a £25 million downturn in revenue for next season after their two-year spell in the top flight came to an end on Sunday following a 2-1 defeat at Tottenham.
At least eight players are set to leave - loanees and those whose contracts have expired - but Pannu is adamant the likes of Roger Johnson, Ben Foster, Scott Dann, Nikola Zigic and Craig Gardner will stay at St Andrew's unless a suitable offer is received.
He said: "If someone offers £3 million for one of our top players, they will be told 'forget it'.
"If someone offers £10 million, £15 million, then we are more likely to think about it - but nothing is cast in stone.
"It is too early really to talk about this sort of thing."
Lee Bowyer, Kevin Phillips, Sebastian Larsson and Stuart Parnaby are out of contract while Alexander Hleb, David Bentley, Matt Derbyshire and Obafemi Martins have ended their loan spells.
Pannu plans to meet Birmingham manager Alex McLeish to discuss their plans for next season in the next couple of days after club owner Carson Yeung decided to keep faith with the former Rangers boss.
He said: "Carson was devastated on Sunday and was not happy but a decision was made to retain Alex.
"I will be meeting him to discuss what we must do for next season. We will do everything in our power to try and win instant promotion."