The quoted cost for the Hafod y llan project in snowdonia was £1.5m.
This compares with an average turbine installed in Europe has a total investment cost of around €1.23 million/MW. The turbine's share of the total cost is, on average, around 76 per cent, while grid connection accounts for around 9 per cent and foundations for around 7 per cent;
Obviously costings and outputs are very much site specific.

https://www.thegwpf.com/type-failure-or-wear-and-tear-in-european-offshore-wind/