For ICT to sell Mackay in this window the offer would have to be £1 Million, with how we are doing in the league and the cups. I would expect the club to hold out for the higher premium due to this being the January window and the teams who would be looking for a proven goal scorer are going to be teams pushing ofr promotion or trying to avoid the drop and would be willing to pay to have him.
However I can see accepting less in the summer depending on how the rest of the season goes, though would still expect about £500k, though if he has a stormer of a 2nd half to the season, £750k+ is a possibility especially if we make Europe.