Do you have some Ebay link of that specific hardware you use
Without endorsing any particular eBay vendor, and just as an example of almost identical HS21 blade servers to what I use (most of mine have E5450 CPU's rather than E5440's, but that's only a few % difference in performance):
http://www.ebay.com/itm/10-PACK-8853-AC1-IBM-HS21-BLADE-2-x-E5440-2-83-GHZ-QUAD-CORE-8GB-RAM-2x-73GB-/200876881184?pt=LH_DefaultDomain_0&hash=item2ec531f520Remember, that price is for a pack of *10* blade servers, not just one.
8GB ECC RAM and dual 73GB SAS hard drives included even (though I prefer just network-booting any slave workers in my cluster).
Then for each group of 14 blade servers, you need a BladeCenter chassis, management module (AMM if you can find one), Ethernet switch module, and depending how many power supplies came with your chassis, a couple power supplies. All of the above are dirt-cheap on eBay too, even the old original BladeCenter E chassis that work perfectly fine for everything right up to the newest blade servers from IBM (albeit with some specific requirements for slot ordering when combining newer HS23 blades with certain power supply types in old E series chassis).
In addition to that, you do also need a decent IT skillset. It's not at all a difficult platform to work with, but would probably be pretty intimidating to someone with no network engineering or data center experience. You manage all the servers through video and keyboard redirection to a web browser interface (via a Java version of VLC), and a shared DVD tray / USB slot that you can connect to any of the 14 blades in a chassis at a time. You can even mount a CD/DVD drive or ISO image from whatever computer you're hitting the management module with your web browser from, and it appears to be an actual hardware CD/DVD drive attached to that server. Makes OS installation a breeze, you never have to get up from your desk to go swap install media.
Don't try to set up a BladeCenter farm in your home though. The (dual redundant) cooling blowers are loud enough to wake the dead. And you do need 208V-230V power as well (might be a problem for some people, not for others). And don't expect to get rich mining YAC either. I *do* have relatively inexpensive power. I mine with them because I have them already for another business doing render farm jobs on film projects, and there are times they're free to do other tasks. If it costs less in power to leave them up and mining YAC, great. Otherwise I'd power them down when no render farm jobs are queued up.
And for those with an eye toward power costs, you can measure and graph the power consumption of every individual blade server and other component installed in the chassis via the management module's web interface.
Okay, this photo is actually one of my HS21 XM blades rather than a straight HS21 blade, but close enough, just trades some extra DIMM slots in place of the 2nd hard drive slot: