This was the discussion between Michael McGrath and the Governor:
"McGrath : cost €78m for 2,600 so you are looking at a bill of €300m for 10,000
Add in the pre review figures, and the cost is €500m?
Governor: Some are very large sums, some are at the low end. That average will conceal a lot"
It would be very hard to estimate the costs.
another big element would be the future profits lost by putting people back on trackers.
10,000 @ 2% of €100k for 15 years = €300m