Buck the liquid phase is lifted by pumping not capillary action. For an 80 MW plant using ammonia as the working fluid Luis Vega estimates that 2,750 kg/s would be used. The estimated capital cost for a 100 MW plant ship is estimated at 2650 $/kw for the deep water condenser design in the MIT thesis. Locally the costs of a proposed hydro dam, the Site C, is estimated at $8.8 billion for 1,100 MW or 8000 $/kw.
Vogtle 3 and 4 for a combined 2,500 MW are estimated to cost $14 billion for a capex of about 5600 $/kw so I think the cost speaks for itself.