Assuming we will ignore the fact that a regular BD disk is a write-once technology. Lets predict the future market in 2 years with some math here. A dual layer DVD is currently around $1.40 for 8.5 Gigabytes of storage, This is basically 0.00 a gigabyte. If we extrapolate this to a 50 Gig BD disk, then this would be the expected minimum a BD would go for in the marketplace. Considering you will be losing 1 out of 10 disks in a pack and the short storage life of optical technology optical is neither practical nor economical when your start reaching HD storage requirements.