So assuming 25 to 45% capacity factor, $10k to $18k per effective kW. Depreciate that linearly over 20 year's and you get 5.8 to 10.5¢ per kWh before maintenance and operations. Given Arizona pays about 16¢/kWh, the project seems likely to be viable.
You are lumping together the transmission and generation costs, which will have different service lifetimes.
Wind turbines are 30+, but advances in technology and falling costs have incentivized many wind farms to repower with bigger turbines far before the end of service life in order to increase profitability.
An adjacent 350MW project from the same owners has a 46% capacity factor and signed a 20-year agreement for $0.04/kWh (they did qualify for the PTC so their 'real' cost is $0.06/kWh) - this project will surely be well under $0.10/kwh wholesale as well:
> In the event Red Cloud qualifies for 100 percent of the PTC, the energy price will be reduced by $2.00 per MWh and the new energy price will be $41.00 per MWh. The price for Test Energy will be reduced to $30.25 per MWh and Excess Energy will be reduced to $16.40 per MWh.
The best estimate was the 50% in the comment with the original link, which would correspond to $120/mile for transmission, which IIRC is right in the correct ballpark.
