Just my two bits, but you don't have to get another Superdrive. You can easily get a slimline slot loader from most any computer parts supply store, such as NewEgg.com and you will probably save a lot. Doesn't even have to be a slimline, since the drives themselves are usually smaller than the casings. Pretty much any slotloading drive will work. Unless, of course, you have a good deal on a Superdrive, then it would probably be best since you are already used to working on one.
http://www.newegg.com/Product/Product.a ... 6827106358Found this one, $50 for a pretty good slimline.
http://store.apple.com/us/product/MB397 ... TY3ODQ5OTYMacBook Air external superdrive is $80.
However, you could also just buy any *Book from ebay for real cheap that has a slot loading drive. People often sell broken ones for spare parts for very little. Titanium PowerBooks and non-unibody MacBook Pros are very easy to come by due to a design flaw that lead to the Logic Board(motherboard) fracturing easily when dropped. I just recently sold three different MacBook Pros that had fractured motherboards for $20 each. You can also salvage the RAM from these things if they have any left in them and sell that.
Just trying to help.