There's no reason to believe that Google's per-household costs are any less. These companies all likely outsource to the same local companies that put fiber in the ground. To the extent that Google has an advantage, it's with uptake rates. Verizon and Comcast have to wire whole cities, pursuant to build-out clauses in local franchises. Google refuses to accept such clauses, and only builds in neighborhoods with demonstrated interest. The economics of building fiber make this a huge advantage. Most of the cost of building the network is in passing by the house, which is a cost you pay whether or not the house subscribes. If your uptake rate is 40% versus 20%, your per-house capital cost drops dramatically.
