Yes, i think that the costs do outway the advanatge of the training.
Problem is that people (staff) will come and go and you're back to sqaure one. Also, as they say, you can take a horse to water but you cant't make it drink. A good friend of mine is an NVQ cleaning assesor and he says that he knows so many of people put on the training by their employers will never take any notice of the training. From his point of view he isnt being paid top care whether they do or not, he is paid to train, so he just gets on with it.
I think that the proprietor of any cleaning company should consider undertaking formal training and they can then train their staff themselves, at least in how to do their specific job (im not suggesting they train them to the full NVQ level or whatever).
Cheers
Stephen