My only expense is travelling (and lunch, venues provide dinner and accommodation or I couchsurf)
January/February/March: 3 month Eurorail pass €1432
April/May/June: Return flight to the US€600, €2042 rental car and €1000 gasoline
July/August/September: Travelling to festivals est. €2000
October/November/December: 3 month Eurorail pass €1432
Apart from the gasoline, they're all Bought in Holland so I can deduct the 19% sales tax. So my monthly travel rent is €574. Not bad I think. Cheaper than staying in one place!
It's not the way to make a fortune of course, but it pays in other ways and I'm not in it for the money.