Who pays for premium gas?

Alright so I have been putting 91 octane in my daily 2018 WRX since I bought it new but living in CA gas prices are climbing to 5 dollars a gallon at some gas stations. So I’m wondering is it really worth it to spend the 40 cents more a gallon? Wanted to hear your thoughts and see if anyone here has done a comparison with 87 octane. Thanks ✌️