Reality is while more money to set aside for education it doesn't mean it gets filtered down.
So for us in Wales for example the money goes to the assembly, which they they decide how to "dish it out" and it gets send to different councils, who then also decide how they chose to distribute it. The way they do that's it's really complex (for me anyway) and they will work out number of children, children with pupil premium, children with SEN, children with statements, children in care etc as well as working out square footage for how much they get towards upkeep of the the school etc. Then when they have made their calculations money is given to the school who will then decide how to distribute it. If they go over their budget it's deducted from the next year.
Schools then get that pot of money, sickness, maternity etc all have an impact on that budget, as well as how schools use the money. So for example, the council will offer central services like legal support, HR support, swimming lessons, music support etc, it's in to each school if they chose to take up all, some or none of these services. Also the programmes schools use, such as reading programme, or even behaviour programmes, they all cost quite a lot, these services seem to cost upwards of £800. Using outside services like asking for educational psychology assessments all cost considerably.
Schools need maintained too, some schools need more maintenance than others.
Parents expect more too, I know I do, I have children with SEN and I expect the school to be inclusive (up-to a point at least), most parents would want that too.
I can only comment on my school but as a Governor we are seeing a real cost loss of about 5% which is likely to continue year on year.
We may have an increase in funding, I don't think we have seen it though (I would need to see the past few years but it's hard to really see as the way they allot funding changes), so for example, county used to pay our council tax, but now they give us the cash in our pots and then take it off us, so we would potentially see an increase but it's taken straight back off us. Our central services increase year in year, so the cost of transport, HR, legal, music, grass cutting, our Clark to governors, etc (I can't remember it all but there are probably 15 or so) all raise yearly, as well as the things mentioned like gas, electricity etc. The things you probably thought the council did for free, we actually pay for.
Hope that helps a bit, I'm fairly new to getting to grasps with it myself but we really are seeing a loss.