The cost to virtualize a host using ESX is $0.00-if you use ESXi. True, you don't get HA/DRS/VMotion but you do get encapsulation as well as an abstraction from the hardware. ESXi is the same hypervisor as the Enterprise one. I'm surprised the author didn't bring that out-it certainly skews his numbers regarding the "cost" of virtualization.
Mr Jones stated:
"ESX is a solution for ease and efficiency of consolidation of small and moderate systems."
That was true a few years ago, but with hardware performance increasing along with the technology in VMware's hypervisor, even very heavy workloads such as high transactional database are being run in the virtual space. For those systems, clients will often run a single VM on a host where you get the best of both worlds: hardware abstraction, VM manageability, better D/R but also better performance since the host is not sharing any resources with the exception of the hypervisor overhead-which is generally only 10 to 20%/