There's no need to include inflation in the power law model. Adding it would essentially layer one model on top of another, which is unnecessary and counterproductive. In fact, including inflation would likely confound the model, introducing additional complexity and reducing its clarity.

The price we use in the power law (the observable) already reflects inflation—at least the general rate observed over the past 15 years. In other words, the observable data we're working with inherently accounts for inflation to some extent.

The power law simply projects the price at a specific future date, whatever that price represents at that time. 

Adding inflation explicitly would not only be redundant but could also distort the model's results and undermine its predictive accuracy.