Aluminum poles are great because they're cheap. I've had my current pair for at least four years. Think about them as disposable poles. No one thinks about their poles. Then again, some people will ski in boots they bought off the sale shelf at Big-5.
Some people are really stupid.
Good equipment, the right equipment for your ability and the way you ski, makes a big difference. But good poles, light ones with a nice swing weight, will make you ski better. And even if it only makes a tiny little difference isn't it worth an extra hundred bucks. When you think about all the money you spend on travel, lodging, lift tickets, clothes and ski equipment, a hundred bucks seems like nothing. I have to admit there is something nice about having disposable poles.