My optical drive is gone too. Unfortunately my MBP is out of warranty, I was to cheap to spend $400 on apple care.
The drive has to be 9.5mm thick. From what I can see on ebay it will be hard to get away with much less than $140 give or take. Frigen ridiculous for a DVD drive. I also price the fan replacements at around $50 each.

All of a sudden the $400 for Apple Care didn't seem to bad.