No 93 octane around here, choice is between 91 octane with or without ethanol. I have the latter delivered to my bulk tank at home for current pump price but that's for my boats. For fueling my Z, I just refuel at the nearest convenience store with the best touchless car wash. Other considerations for that decision matrix might be best coffee and/or best breakfast burrito.
My town and the next closest one only have one Irving station each, so usually Irving 93. A few towns away, they have Shell and Mobil, so sometimes I get gas there.
Just to provide some perspective: Sunoco GT 100 octane race fuel is $13.38/gallon at High Plains raceway in Colorado. My T3-spec 350Z finished second and third in two SCCA Majors races over the weekend, and is currently tuned for 100-octane fuel. I may have to think about going back to a 93-octane tune if race fuel continues to escalate.