What do they mean?
They start with a splendid old saying, the kind we all heard at our grandmothers' knees, such as "a penny saved is a penny earned", or "look after the pennies and the pounds will look after themselves", and turn it into something which might mean the same thing, or might not, depending on the exigencies of the moment. The core meaning is, of course: buy as little of everything as you can, and as cheaply as possible. This is the "what kind of 40-watt light bulb would you like just the one of" economic principle so beloved of politicians. They can then, through another process of cruel and unusual linguistic transformation, present this as making savings by reducing inefficiency and eliminating unnecessary expenditure.
Needless to say, there is no real saving at all. In this case, it is simply shunted over to the National Health Service, which will have to deal with the consequences of a generation of students all trying to study by the light of one 40-watt bulb. It does, however, mean that a shadow education minister will not be able to embarrass one of Tony's finest by waving a requisition form for two 60-watt bulbs before a horrified House of Commons, while thundering on about wastage of taxpayers' money.
But then again, somebody might decide to investigate the dreadful decline in standards of literacy, and discover that the reason children can't read is that they can't see anything in the gloom. This would never do. So best value also means (without prejudice to the above, overriding, definition): make the most efficient use of resources, while ensuring that all the children can read properly. Of course, this neat balancing act has to be done by the schools themselves. That way, if anything goes horribly wrong, everyone can blame the teachers for not doing what they were told. This is because all the people in the higher pay grades took heed of their grannies' other old maxim: when the chickens come home to roost, make sure they're in somebody else's barn.
Tim Homfray email@example.com