Birmingham chairman Peter Pannu has insisted that the club will not be disposing of key players at cheap rates.
The Blues - relegated from the Premier after two seasons on Sunday - could lose more than eight players, with four out of contract and four more on expired loans.
Key stars such as Roger Johnson, Ben Foster and Nikola Zigic could also leave if the right offers come through from Premiership sides.
"If someone offers £3 million for one of our top players, they will be told 'forget it'," said Pannu. "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."
The club previously confirmed that manager Alex McLeish's job was safe for next season.