If you can push your budget to around $250 you can get some really good quality designs off crowdspring. I've used a few crowdsourcing places and I find that crowdspring have the best quality designers. For the premium you also get a more professional experience. All crowdspring designers sign a contract to ensure that the design belongs to you and they have not copied from another source.
If you are stuck on the $99 budget, I'd give Mycroburst a go which is also a crowd sourced design service but they charge a lower rate to enter their network. They still have some pretty good designers. You find that quite a few would have profiles on multiple sites, but obviously they will always apply for jobs that are worth more, and hence why you can get some better quality designs by paying $250.
The best thing is crowdspring will give you most of your money back (everything minus listing fee) if you receive less than 100 designs.
The websites are:
www.crowdspring.com www.mycroburst.com www.99designs.com
If you want to go down this path, theres a few things you can do to ensure you get what you want.
1. Be specific about the style and feel of your design. In your brief put pictures of logos you like. Specify whether you want a font only logo or not. Any colours your prefer etc. You are more likely to get what you want.
2. Invite designers with the particular style you want. What I do is surf through all the existing projects on the site and keep an eye out for really good submissions. I then private message the designer and invite them to my project (copy and past your project URL). Do about 20 of these and a few of them will come through and submit some quality designs.
So thats it

It's a pretty good option (it's not great for designers because many of them work for free) but certainly a good option for start ups. If you are feeling generous some sites allow you to donate money to designers that didn't win
Thanks for reading,
Wendy