It's a little tough to give a detailed price quote since only three of these hats exist and they rarely show up on the market, but an accurate price can be determined by comparing regular Demoman hats with their robo counterparts (Sober Stuntman/Cyborg Stunt Helmet, Buccaneer's Bicorne/Bolted Bicorne, Fro/FR-0). Robo hats tend to be valued slightly lower than their normal counterparts (see Bicorne, Fro for examples. http://backpack.tf/unusuals). The value for this hat's robo-counterpart is 2.2-2.9 buds on backpack.tf. There are a few Power Surge Cyborgs on outpost for 2.5-3 buds ( http://www.tf2outpost.com/trade/17252713 , http://www.tf2outpost.com/trade/17392838). Given the slightly higher value of regular hats to robo hats, a value of 2.5-3 buds seems very reasonable.