• Total invested (not including equipment I had on hand like the RPi and a few of the hubs): around $1187
• Power draw: 82W
• Income per week:  0.046 BTC at current difficulty
• Hashing power: 9.5GH/sec

9 of the erupters were bought on amazon for $35 each
11 were bought across several ebay auctions around $50 each (varied per auction)
bitfury was bought on ebay for 280

In the next few days I also have a block erupter blade that I also bought on ebay which will bring my total hashing power to 19.5.

Things that need to be improved on this setup:

• RPi struggles to keep up with this many USB devices. Another RPi (only $35) would make it more much stable.
• No more USB erupters, for what I paid for them I could have bought two block erupter blades and have double rate I have now
• Overclock the block erupters. Replace the oscilator with 16mhz to bring them up to 400-440MH/sec which would add ~2Gh/sec total

So far the bitfury has responded well to overclocking, getting close to 2.9Gh/sec after replacing R15 with an 850 ohm resistor

http://i.imgur.com/BURdODS.png