Men’s Classic Style

Question
Why Should I purchase an extra pair of trousers with my suit?

Answer
I always recommend purchasing an extra pair of trousers with a custom suit. My reasoning is

The fabric from which the suit is cut is unique and likely to be discontinued by the mill eventually. [...]

Note - the following is a Google Knol I wrote a while back; while a decent introduction, I feel it can be improved upon and welcome any comments to help me in that endeavor.
Introduction to the Men’s Suit
The men’s business suit is the most universally appropriate item in a gentleman’s wardrobe. There are few events [...]