May works rota

So I am now getting the staff rota organised for May. In theory I should be working the days of the 6th place play offs and the day of the final, that's the way it rolls. To move staff now to fill the gaps would cost £60 per day but nearer the time would cost more as it would be 'extra' pay for working their day off. And if we finish 5th I'm off to see Mrs Wonga.
Advice