It does make me feel better and reduces stress. I don't want to add aftermarket additives and would rather have it in the gas from the pump. It would be one thing if it were contraindicated for reasons other than cost. If it's only money, then it's not a barrier. It's not like I'm buying ten dollar a gallon 100 octane. It's just premium fuel at a local gas station a few miles down the road, located a few blocks from the Subaru dealership.However, as with anything, go buy whatever you want! If it makes you feel better and reduces stress, then go for it!
For some people it's well worth it to pay a thousand dollars for paint protection film, or have pin stripes painted on, or get nice wheels. To each his/her own. For me it's premium fuel, frequent oil changes.