"There's a package there that could lead up to £2million," he told BBC Scotland. "There's a certain amount guaranteed and a certain amount with add-ons.
"Celtic have asked for permission to speak to the player, that was all, and that permission was given.
"Celtic know the price that we are asking.
"That price was a decision made by (Kilmarnock chairman) Michael Johnston and the board, that I agreed with.
"He's been fantastic in the Premier League for the last couple of seasons, he's also a full Scotland international and what we're asking for is fair."
"They are quite entitled to value a player at whatever they like, there's nothing wrong with that, but never at any time have Rangers met our asking price which they've known from day one.