The best price pay people on ebay as many don't calculate the hardeware break even. You would get probaly 2500 USD for 120 GH.

http://www.ebay.com/itm/1st-of-2-Avalon-4-module-ASIC-bitcoin-miner-110-GH-possible-IN-HAND-SHIPS-FAST-/331045667320?pt=LH_DefaultDomain_0&hash=item4d13dc01f8

If you calculate with a diff increase of 30% every 10 days than the FAIR value is about 9.5  BTC without power costs.

Did we save only 35 BTC? 60 % of 95 BTC should be a few more, right?