Thanks for replying. I was kind of thinking that since the reduction in cost for block booking was so small, that the risk must also be small. But I guess it is more a reflection of the margins involved, rather than the risk to the student's money. I think I will just pay by the hour.
From my trial lesson, I already recognise that heli flying is a totally different kettle of fish to fixed wing, particularly since I have not had to touch a rudder peddle (other than take-off, landing and engine failure) since I stopped flying light aircraft nine years ago. Fine tuning those tail rotor inputs is definitely going to be my greatest challenge for the hover.
As for continuity; I could take a lesson every day I am home, but I personally think that would reduce my learning curve. I think I need time to reflect on a lesson, in order to absorb my mistakes and learn from them.
Anyway, as predicted, I suspect I am going to have very little spare cash ever again...