If you have rigs that can do less, like even as low as 100 khash, still place a price
I could get something like this together out of parts I have for sale.
See my thread here: https://bitcointalksearch.org/topic/used-5870s5850s-pcie-risers-mobocpumem-combos-psus-accepting-offers-276475
You would need the following from that thread:
1 GPU
1 Mobo/CPU/Mem Combo
1 PSU
I don't have any cases, this would be an open air rig.
Take a look at the options I have available and let me know if you're interested. You can mix and match parts to make as slow (300Kh) or however fast (2500Kh+) a rig as you would want.