Eh, that doesn't math out. It's the bandwidth per storage density (or ultimately per price) that matters.

If you have great cost per byte but your bandwidth per byte is bad enough that the price per byte doesn't make up for it then you have an issue.

They've started making hard drives with multiple heads because of this issue, they increased density to the point where it's not useful to continue adding density if it doesn't come with more bandwdith.

*RAED

Or maybe RAEND