I had a cabinet at the colo data center that was formerly Enron's data center - super thick pipe to the public Internet, in a data center built to survive nuclear war. I had 17 servers and a Federal Reserve quality hardware firewall, total cost of hardware was about $55K, the colo expense of $600 a month, and my team of two spent perhaps a day a month on maintenance. This was in contrast to $96K per month for the same setup at Amazon.