Like what ones?
Yellow Jacket (based on the nanofury design) going for $90 a piece getting you $41 a Gh/s
Also the ANTminer U1 hashing at 1.6Gh/s @
BTC0.07
For 3 times 2.3ghs nano's you would need 4.3 so you'll need 5. Costing
BTC0.35 which at current rates is only $350 getting you $44 a Gh/s
You charge ~$190 a piece which is getting $82 a Gh/s