The price of electricity includes a component for amortization of the capital costs for the generating equipment. You don't build a plant for free, no matter what kind it is. That cost has to be recovered in the rate base. So, you do care about the powerplant's capital costs, because it determines in part the rate you're paying.
Yes but that is all summed up in the price of the power contracted by the windfarm investors. That really is the bottom line, how much will you sell the power for? If you have to have 10 cents per kwhr to get investors, you aren't going to get investors because you won't get many customers.
So now you're saying the cost of the plant does matter? If so, I agree. But you made a declarative statement earlier that the cost of the powerplant doesn't matter, what we pay for electricity. One affects the other.