There are a lot of good comments here and many with different take-away messages. Speaking from experience from a similar situation, my own take-away is a conglomeration of @mcargian, @jellicle, and @RiderOfGiraffes: $550 for 30 hours is a flag, and if you think a contract is going to ensure a quality and timely delivery, you should probably focus on deliverables and milestones in the contract with a 50% up-front, 50% on-delivery pay-out.
I certainly don't want to belittle $550, as it sounds like it took you a significant amount of time to accrue, but there is a deeper lesson than simply "hire an attorney".
I certainly don't want to belittle $550, as it sounds like it took you a significant amount of time to accrue, but there is a deeper lesson than simply "hire an attorney".
Pro-tip: http://news.ycombinator.com/item?id=1845648 followed by "... but it's most important that you learn."
P.S. Best of luck and shoot me an email if you are looking for designers. I happen to know several.