Oh yes, I'd already forgotten about that Gomev.
I came back to update about my figures - I realised due to extended holidays (5 - 6 weeks) in March and October, and solar panels, my actual figures won't mean much really.
But for Jan/Feb/April I used 772 cheap units and 768 expensive ones, and in July/Aug I used 525 cheap units and 286 expensive ones.
Car charging, dishwasher, washing machine and tumble dryer all (usually) happen in cheap zone. Also, fortunately, as at the moment my cheap zone runs from 21:30 for 4 hours, some of my evening activities (TV, hot drinks etc) end up cheap - I know this won't last.