http://news.bbc.co.uk/1/hi/education/10612765.stm
So there is a bit of a Daily Mail going on about this Head who by all accounts took a school that was bottom of the league to comfortably in the top in only a few years. Whilst its obviously not all by his own doing, he was the person who would have been held accountable for its failure if it had. He has obviously been able to create an environment where teachers are able to flourish and students learn.
That 200k is peanuts in the saving that would be made by just a few of the children that will have say avoided the interaction time with the police and criminal justice system.
It seams like he has done a stand up job, and imho a one off bonus of £100k probably doesn't do it justice alone, if the school is still thriving with him at the helm 5 years later, another 50k+ (discounted) should be in order. Then hopefully he will be able to hand over the reigns to someone less gifted and turn round another school, £200k is a bargain for that.