I have a feeling that the type of business is severely skewing the data to make Silicon Valley higher. Also, what do they consider "silicon valley"? I live in San Jose, which could be considered Silicon Valley. There's also Cupertino, Palo Alto, Santa Clara, Sunnyvale, Mountain View, and many more.

I suspect that there's an unproportionally high number of higher up business travelers that go to Silicon Valley, who spend more on travel by choice and not by necessity. Lots of money based there, not to mention all the venture capital firms in Palo Alto and Menlo Park.

I think we may find that there's a moderate number of people spending a lot of money, while the majority spends a lot less. Food, transportation, and lodging isn't any more expensive around here than most other major metros.