Unfortunately, the power usage is ridiculous, something like 20 kW. That's what typically makes old big-iron impractical. At the mid-range, used hardware is even cheaper: you can pick up old 12-core, 48-GB-RAM Itanium boxes for the cost of a Chromebook (~$200-300). But they take so much power that you don't end up saving anything over buying a dual-Xeon new, at least if you keep it on. Also, everything is very heavy and a hassle to move.
Unfortunately, the power usage is ridiculous, something like 20 kW. That's what typically makes old big-iron impractical. At the mid-range, used hardware is even cheaper: you can pick up old 12-core, 48-GB-RAM Itanium boxes for the cost of a Chromebook (~$200-300). But they take so much power that you don't end up saving anything over buying a dual-Xeon new, at least if you keep it on. Also, everything is very heavy and a hassle to move.