This sounds quite complicated for a not-too-good mathematician like myself.
However, I'd start off low (due to my own funds) then work up. I've always considered this to be an easy way to make money but never given it a go.
I'm gonna do my research, study the information and then give it a whirl.
"You have hardly anything to lose but perhaps a lot to gain..."
Is the the correct thread to find the relevant information?
http://forums.moneysavingexpert.com/....php?t=2658533