So, most people know that I (Tim) enjoy a good spreadsheet... i've been keeping track as closely as possible of our expenditure during the trip and here is the breakdown (just in case anyone else feels like doing the same thing!).
The total came to just over 8,000GBP (with a bit of adjustment for a very fluctuation dollar to pound). It seems like a lot (and it is!) but would have been alot more if the snow had actually been any good. WWOOFing and HelpX were also very useful in saving pennies, but they were more than that - they gave us the opportunity to meet and be with people in a completely different way than we had ever expected. Right then, America here we come!