We picked up a 100 box of slim jewel cases at Costco for $17.99. The covers are yellow-tinted, though.
I routinely see 100 packs of CD-Rs (80 min) at Best Buy for $10, after rebate. I picked up a pack myself a few weeks back- Imation. No coasters, so far, and I've used about 50 (birthday invitation for my daughter).