This popped into my head about four or five years ago, and then about two years ago I found this video. It illustrates my opinion beautifully. ...But I'm still going to rant a bit:

The word designer appears in front of a lot of things, clothes, electronics, furniture, and everything else you can buy. I find it annoying. It doesn't actually mean anything. Everything you buy was designed by someone. Your Television, your socks, everything. And yet if it says Designer in front of it, they charge a bout twice as much. Let me tell you this. Knockoffs are just as good, look the same, and cost much less. Don't buy something that costs too much because some yuppy's name is on it. Buy the less expensive ones.

If you really like a specific designer, or designers, that's fine. Buy their stuff, but don't buy things because they are Designer whatever. It's just... stupid.