@ZunePod - Yes, I've paid between $200-$250 for icon designs using 99Designs.com. It is the one thing users see to grab their attention so I try to invest a little bit into this. Good designers are valuable and $200 is not a lot of money especially considering they make changes for your and in general follow the extensive process the previous poster has described.
I have used places like iStockPhoto.com to get cheap artwork for icons and if you are broke you could always try that. That will only set you back $1-$20.
But, in general I think designers have a valuable skill (just like programmers) that is worth investing in.
