Do you have a secret to building cheap rigs? I'm not being sarcastic, just really wondering how it is possible to build a 4x270x for under a grand.  by my calculations:

4x270x Rig   
ram   $25.00
processor   $42.00
mobo   $60.00
psu   $210.00
hd/memory stick   $20.00
# of gpus   4
gpus total cost   $800.00
hardware (rig/case)   $30.00
adapters   $30.00
   
   
Total   $1,217.00
$/KH   $0.68

Always interested in info regarding cutting down costs on rig building.

Considering 3x290x rig in comparison:
3x290x Rig   
ram   $25.00
processor   $42.00
mobo   $60.00
psu   $210.00
hd/memory stick   $20.00
# of gpus   3
gpus total cost   $1,887.00
hardware (rig/case)   $30.00
adapters   $30.00
   
   
Total   $2,304.00
total KH   $2700
$/KH   $0.85

so actually seems to be cheaper builds on the 270s, obviously costs would go down with more cards, if u compare 7 cards u get:
7x270x = $0.61/KH
7x280x = $0.66/KH
7x7950 = $0.76/KH
7x290x = $0.80/KH

I find this interesting, I had just assumed that 280x was best due to everyone saying it was next best to 7950s.  Obviously this doesn't consider power consumption, but i believe the 270x are pretty light on power anyway.  But obviously you would need a lot more cards to make up the same hashing so maybe power consumption is a big factor.