Just found a source for T7500's @ $125... I see a single mention someone earlier in the thread; just wondering has anyone had success turning a T7500 into a mining rig? They seem to be close to the T5500 in design...
$125 ?! I can't find them for any cheaper than 275+ EUR

so that's a steal! Especially considering this ...
Dell T5500 is the equivalent of a HP Z400-series
Dell T3500 is the equivalent of a HP Z600-series
Dell T7500 is the equivalent of a HP Z800-series
... and T7500 seems to come with 1100W PSU by default. And with two PCie 16 slots with upto 225W (instead of 150W of HP Z400) out of a total of the similar 4x PCie according to
http://www.dell.com/content/products/productdetails.aspx/workstation-precision-t7500 . It sure has great perspective.