At 120K per year over the three year accounting life of the hardware, that's 360k... how do you get to 1.7M?

It seems unlikely to me that they'll never have to retrain their model to account for new data. Is the assumption that their power usage drastically drops after 3 years?

Unless they go out of business in 3 years that seems unlikely to me. Is this a one-off model where they train once and it never needs to be updated?