I believe I've found the holy grail on USB hubs for miners. Orico makes a 10 port USB 2.0 hub (P10-U2), but never advertises is. I just got in contact with my rep, and will be placing a very large order on them. Cost is going to be significantly lower than any other hub on the list on the front of the page. The PSU is 12v/3a, and is a spitting image of the P10-U3 (which ranges in price from $50 - $65 online).
I should be able to sell them for between $25 - $30 USD including shipping. I am planning on buying at least 100 of them to save a little money on shipping to me (which is likely going to cost about $3 - 5 per unit).
I haven't seen anyone else mention this hub, so I thought I'd speak up. I've had great success with Orico, since they're the ones behind the major favorites like Anker and Satechi.
I told you about this hub. I buy 5 piees for me yesterday and say you about this model.
http://www.ebay.com/itm/10-Port-Powered-Portable-High-Speed-External-USB2-0-Hub-Multi-Outlet-Power-Strip-/350881808003?pt=US_USB_Cables_Hubs_Adapters&hash=item51b22f7e83
27 usd free shipping on ebay
http://www.newegg.com/Product/Product.aspx?Item=9SIA1SK0YU3538&Tpk=etekcity%20p10-u2
27,46 usd on neweggs.
the most usb's ive been able to run on these is 7
12v 3A = 36W
assume about 50% internal losses = 18W stable
2.5w per erupter = 7.2 devices
If you daisy chain then you will loose 2 ports, still not bad for the price.