I stopped reading the blog, but in the past I noticed if you add back in many of the spending categories he either left off his budget (or were implausibly low) like home improvements, business entertainment expenses, travel, dental checkups, gas usage compared to long driving vacations, free gifts the rest of us would have to purchase, income taxes and health care he probably actually spends more than average.
I have books like The Tightwad Gazette and while I may not want to be quite that cheap, every description of their actual spending habits in three volumes of books all seem pretty plausible.