When you move from physical to virtual desktops, you are at the same time moving from a distributed to a centralized storage environment. Chances are very good that most of the storage devices attached to your current physical desktops are IDE-based storage. Your centralized storage, however, will be based on enterprise-class storage, not only because you will need that to support the scalability you require, but for a number of other operational reasons that have to do with performance, high availability, recoverability, and manageability.

IDE-based storage is widely available for roughly 10 cents/GB through retail outlets like Fry's. Enterprise-class storage is going to raise the cost per GB of storage a minimum of 30x if youre looking at SATA based storage, and as much as 100x if you're looking at FC-based storage that supports critical centralized storage functionality like high performance caches, sharing, multi-path I/O, and disk-based snapshots. You can't create the centralized data store you need for VDI projects without using enterprise-class storage technology. Therefore, you will need to factor in the necessary additional costs when budgeting for your VDI storage platform.