I bought an external USB Blu-Ray R/W (Panasonic USB 2.0 UJ220B Blu-Ray Burner/Player) on ebay for USD190 (incl. shipping). Can't see why this shouldn't work on an Apple (but then I don't know squat about OS-X). Oh, and you can get it in white.
You should be able to get readers for a lot less.
My drive hasn't arrived yet, will just have to see whether it gets stolen or not, there has been a lot of theft in the SA Post Office lately.