http://designoutpost.com - you pay a set fee, and a slew of designers make a logo based on your description. They then iterate till they get it right, and don't get paid till you choose one. Pretty good methodology, i've tried it twice and got what I wanted both times.
We had good luck getting interesting designs from this site, we are actually in the final stages right now. We were waiting to complete the full purchase before posting about it. So far I would highly recommend it as an interesting way to get a large variety of interesting ideas. The costs range from $150 to about $300 or so for most logo contests that I have seen.
If your interested I highly recommend browsing other peoples public logo forums to check out the kind/quality of work being produced.
We ended up paying $180, if you want to see the final result of that we got, we just made a post with it. If you look through the flickr pictures you can see some of the options we received.
