Just bought my 2004 Crossfire!

After driving by the dealership on my way to work for a couple of weeks, I just had to have it. I put all the money I had towards the down payment, just to find out that the tires on the car need to be replaced... The price quotes I'm getting are all over $1,000 for the set. I will admit this is my first sports car - I've always driven SUV's and know nothing about cars. If you know of a good brand/style of tire that I can use that would be under $500 for the set, I would appreciate the info.
Thank you!!
- Eva -