I think the argument being made here is you need a home/apartment and vehicle (at least where there isn't public transit) but it is hard to argue you need to go into debt every time you see a cool reptile.
That being said, we are looking at buying our first house, but I've been having a lot of trouble find and holding down a job since 9/11 so we are buying a house solely based of my husband's hourly salary. When I'm working, I make 3x what he does, but we are not even going to consider that as a possibility - we are buying only what he can afford alone. Sure, he could get hurt at work and we'd lose his income, and in a few months we'd be struggling when the saving ran out, but since in that time we wouldn't be buying any animals, won't be going out to dinner, and no new video games, I hardly see us as "Spending money we don't have" on a mortgage. Just my 2 cents.