I've been thinking about getting some of the Quanta Windmill servers they have on surplus.
As long as my A2 units stay profitable though, I'm not in a rush - don't have a lot of 220 available in the current space and the A2 make more per watt used at this point.
The thing I liked about The IT Mart is that their prices seems to be somewhat negotiable. Especially on more esoteric stuff.
Ordering and inventory systems can use some improvement though. They also list some items on eBay and take offers.