Did one better and installed a "Superdrive"
Basically, take a look through xlr8yourmac
. I selected the Toshiba SD-R6012. Bought a new one from eBay for about $170cdn.
As long as you have the dvd shell/interface from your pismo, it's about a 15 minute job of swapping the insides of the drive. There's some decent info on the above link too.
The one downer is getting the old faceplate on the new drive. If you can live with that, it'll save you hundreds off the mce offering.