Please note that the online BB ordering system will only allow you to place a single drive in your cart at a time. I had the same problem last week when they were on sale, however in-store you can purchase as many as you want.
I bought one of these exact drives a while back and was disappointed in the drive. The plastic surrounding the inside of the connection (not metal-plastic) is thin and bends easy. My drive worked for about 2-3 hours before no longer being recognized.