Or we could just... walk away?
This is a moot point, you could too.
Thing is, your group were found out in the finals due to a genuine lack of midfield depth. If you don't bring Gibbs in, you will go into 2017 with the same group of mids but a year older and missing Lyon. I cannot see how you will bridge that gap in your list.
This group is ready to challenge but they won't if they don't have all the components needed. If you win a flag in the next two years on the back of securing Gibbs, no-one is going to give two hoots what it cost you to get him, but they will all remember that flag.