Also depends on what you're buying. Music stuff? Hunting equipment? Cars? Girlfriends? :-D . Kidding, of course.
With me and my music, I've noticed that if you buy cheap, you'll get cheap. But this doesn't always apply to hunting equipment. The bow I shoot is very quiet and very accurate, but it cost me only $300, a fraction of the cost for a Mathews, so to say.
So it all depends. It really does.