That being said, I'm a college student, with a college student's budget. I've almost plunked down the money for a copy many times, but twenty bucks would feed my wife and I for a week or two. We just don't have the funds available to throw around that kind of money, even if it would be a significant investment in my career. Add on top of that the fact that the thing is a tad out of date by the time it's printed, or the fact that every writer in the English speaking world uses WM as their go-to list of contacts, upping the competition for each one, means that maybe it's not the best use of my money.
So, instead of buying one, I use the copy here at my library. The only problem was that the library had a copy from 2001 and a copy from 2004. My best bet was three years out of date. Since I haven't been querying quit as much as I think I should, it hasn't been a huge issue, but it still bothered me. In fact, the very fact that it was so out of date may have contributed to my slothfulness in querying.
Those days are over now! As of today, the library is now equipped with a 2006 Writer's Market. Hooray! Granted, it still has all of the drawbacks that I already mentioned - out of date, used by everybody and their grandmother, really, really big - but it's still an improvement. Maybe someday I'll just buy my own. Until then, I'll stick with this one.