Of course he uses money as a measure of success, he's an investor!
Buffet did an interview on CNBC some years ago where the question where he was asked about success and his reply was something to effect of "Success doing what you love and doing it well".
This rings true to me.
A little anecdote told by my father in law, who was Buffett's pilot for a time, tells of Buffett being welcomed home to Omaha by a hostess. On remarking that he'd lived in the same house for 50 years it's claimed she said "Gee! You must have a lot of equity in that house Mr. Buffett."
Whether this speaks to the unpretentiousness of Warren Buffett or the unworldliness of the hostess is an exercise for the reader.