With drives and storage competition so close together, one of the factors a user has to make a decision on is cost per Gig (or cost per Gigabyte) while comparing the drives.

The cost per gig is simply calculated by dividing the total  cost of the drive by total number of gigabytes.

So for example if you were buying a 1500 Gigabyte hard drive for $130 (inclusive of taxes, shipping and any other costs)  then your cost per gig for that hard drive will be 130 / 1500 which comes out to be 0.86 or roughly 8 cents