For unfair dismissal, the IT would only have the governance to order the club to pay c£80k, if they found in his favour. That is the extent of their remit.
In court, Poyet would be able to claim much more (whatever the figure is) - i.e. the rest of his contract and so on.
http://www.oddschecker.com/football/football-specials/sunderland/next-permanent-manager
I think these odds were given before Di Canio was booted. They seem to have odds for all teams in the Premier League.