For large purchases, and for large corporate purchases, it's nearly essential.  If a price is on the website, many higher-ups relegate it to the "home user" side of the market, rather than the over-engineered nastiness they usually buy.  I've personally seen it a few times, and have heard it "straight from the horse's mouth" from one of my higher-ups (on a university campus, under a relatively prominent (state-wide) IT-like manager).