The cost of wave energy is almost invariably ignored by industry proponents. But occasionally a factiod does pop up. For example, the Daily Astorian points out that the electric cable connecting the proposed wave test site to the grid would cost $2 million a mile. They hasten to point out that the government will not be on the hook for those costs.
The UK's Carbon Trust sees wave energy as costing 4 to 5 times offshore wind.
"The UK’s Carbon Trust sees the levelised cost of offshore wave energy (with a 15 per cent discount rate) at 0.38-0.48 pounds/KWh for wave energy and 0.29-0.33 pounds/KWh for tidal, compared with 0.09-0.10 pounds/KWh for nuclear and offshore wind."