“What, Dave, more?” you ask. Yes, I’m afraid so. I’m afraid so. Trying to keep it short this time.

All builds have a server, 4+ disk RAID5, and offer flexible storage expansion to keep them around for about 2 to 4 years. Each has a “Priced from scratch” number. Remember that this includes 4x $100 drives (currently the 1.5 to 2TB range) that you might already own, or be willing to substitute your old 200-300 gig drives for instead, or whatever. I think you get the idea.

Optimize for money, with Mac guest:

Priced from scratch: $1900ish

• Mac mini (any flavor), add RAM to 4. ($600-1000) ($300-700 on craigslist)
• VMware Fusion ($70)
• Mac OS Server (presumably the license you got from buying the Mini Server, right?) ($500 or included with mac)
• Drobo via local connection for the host, guests live on the Drobo ($400)
• disks ($400)
• Apple USB dongle (technically support is only for the MBAir, but it works. Trust me.) if you want to use a VM router. ($30)

Pro:

• Low electricity.
• Low heat.
• Few surprises.
• Drobo adds the ability to just keep expanding your storage for either more VMs or more space on them without having to worry about iSCSI components losing power between you and the array.
• Easy UI and remote control with Back to my Mac and/or VNC.
• Low TCO – macs depreciate slowly. If it’s time to upgrade to something more powerful later, you can sell it.

Con:

• Few server-quality expansion options.
• No internal high-speed RAID.
• The Drobo will only hit 40ish meg a second, but honestly for home, you’ll probably not need that much all the time.
• VMs limited to 100mbit connections.

Optimize for money, without Mac guest:

New

Priced from scratch: $1550ish

• DIY Intel Core2 quad based on LGA775, 8 gig of ram (priceout on newegg: $550 + hard drives)
• ESXi $0
• Adaptec 2405 RAID controller ($200ish) and SAS case/enclosure ($400)(or other supported card/case/enclosure setup)
• disks ($400)
• Optional substitution: iSCSI remote storage (like FreeNAS or Drobo Pro)(-1000, +cost of chosen iSCSI target)

Pro:

• ESXi is really the right tool for the job.
• Can sometimes get away with a very cheap hardware build.
• Some VMs can go up to gigabit connections if you absolutely must have it.
• Optional iSCSI/fiberchannel storage growth paths open to you.
• Faster and more powerful than the Mac Mini option, but you’ll have some surprises building the box. There is always a hidden surprise.

Con:

• ESXi doesn’t support lots of cheap hardware, so you’ll have to be careful about the hardware you pick.
• You still need a separate windows box/VM around to manipulate things, or get really comfortable with the VMware CLI.
• Higher overall TCO? It’s usually harder selling a used medium-low power server in two to four years.
• It will use more electricity for those extra cores and extra RAM, but if you do video work with this box, it may pay off to have them.
• Electricity/heat in the middle range. Initial expense may convince you that the maintenance is worth it.
• Doesn’t support the mac guest, but there are alternatives to OS X Server’s two most attractive features for the home: iCal server and TimeMachine on flexible storage. Dang, that’s a pro. Moving on.

Used

I will point out that the previous generation of HP/Dell ESX supported servers are regularly on craigslist for cheap – usually $400 and under. Rackmounted and everything, but usually running “real” SCSI disks, very loud, very hot, very small. They still will need $1000 in storage, the same as the rest, so buyer beware, but if you’re just going for the VM server and can skip the storage, you can get in on the cheap.

Optimize for speed, with Mac guest:

Priced from scratch: $5000ish + 2 kidneys

• Mac Pro 8-cores Nehalem, 16GB RAM ($kidney)
• Mac OS X Supported RAID controller plus enclosure and disks. ($other kidney + $1000)
• Mac OS X Server (bundle with Mac?) ($500)
• VMware Fusion ($70)
• disks ($400)
• Alternate to RAID controller and enclosure: Drobo plus disks ($300-3000)

Pro:

• Fast.
• Very fast.
• Lots of memory for lots of VMs.
• Lots of very fast storage.
• Potential no-downtime storage growth.

Cons:

• Dude, you’re out of kidneys.
• Limited hardware choices for SAS RAID.
• Limited iSCSI options.
• Speed gain over Core-2 chips might not enough to warrant price differential unless you do a lot more math than most of us do.
• TCO for depreciation can be large when initial investment is also large.
• Hot. Cooling is expensive.

Optimize for speed, without Mac guest:

Stop. At this point we’re priced out of reasonable home options. A similar spec to the Mac Pro can be built on Newegg for about $1200 with a RAID card. But at that point, you might as well get one of the Asus barebones servers that are fully VMware certified and attach to external RAID storage. When I get as far as this, I know we’ve exited “home” and reached “business” expense levels, at which point the economics of consolidation have already broken down. How many systems do you have to sell and turn off – in your house - to cover the depreciation of a Mac Pro, over the same for a Mini?

Hope that was short enough. Comment away!