I've never kept track of how much money I've spent on tours. When I started I spent as little as possible. Now I don't worry so much. How much one spends on a bike tour can vary wildly, depending on the individual.

The one expense that seems to be fairly common to all is food. I don't mean we all spend the same amount on food. I mean we pretty much all develop enormous appetites on tour and eat significantly more than we do at home.

On my first long tour - 4 weeks - that was a surprise. I had some sort of budget goals (I can't remember the specifics) and my food costs were far more than I anticipated.