Antec 300. Watch newegg for free shipping deals. You're going to pay closer to $60, but it's worth it. Then just pick up a couple Yate Loons for the front and you should be golden. That will put you around the $70 mark, but this is your best bang for the buck setup imho.
I found a guy selling a Thermaltake Armor Full Tower for $50 about 1 hour away from me. I'm going there anyway Sunday so i might try to meet him and get it. Thats a steal for $50 right? But I wonder if the airflow is as good as the newer cases...