The UK has just finished building the Hornsea Project 1 offshore wind farm. [1]
It had a projected cost of $5.2 billion for a nameplate capacity of 1.2GW and an actual average output of 0.46GW. Scaled to the output of the Flamanville mess (1.6GW), it means that a wind farm with equivalent average output would cost about $18 billion. Though I imagine that the average lifetime of a 174-turbines wind farm over an area of 630 sq kms in the middle of the sea might be shorter than that of a nuclear plant.