I am not qualified to talk about Pay for Teachers, but pay is but one aspect of the strike action, for there are others. Be their pay be good or not there is a shortage of teachers and other forms of support in schools. Schools are also extremely short of many other resources vital to the actions of teaching and much of this is down to the continued spending cuts imposed by Governments.
No matter how much one is paid they need all the resouces available to do the job completely and this is not occurring currently.
Source: England’s teachers among the best paid for fewest hours in Europe