cheap is relative
What is cheap x86 servers? My fairly loaded HP DL380Gen8s (24 core/48 thread 192GB 4x10G 2x8G FC w/4 hour onsite support) and vSphere enterprise plus are around $30k each. The cost hasn't changed too much since we bought our DL385 G7s 3 years ago (other than the systems are about 2x faster than our 3 year old boxes in the same power envelope)
Maybe to some that is cheap, maybe to others it is not. To me it's reasonable with the ability to get good consolidation ratios out of them, and they have been *extremely* reliable.
Though HP 3PAR has done pretty amazingly well at being a low cost leader in all flash systems recently(relative to their main competition anyway)