Milne will sell him for around £1.5 - £2m no doubt about it.
McInnes probably gets a decent input into any offers that come in for players but Milne will sell when he wants.
You could also say that thanks to Alex McLeish that Scott McKenna’s profile and transfer fee has certainly been upped a bit. McLeish has given the lad a platform to encourage a very decent career and he certainly believes he is his main centre back now.