I'd do a lot better if I went in somewhere to get a cup of coffee and sat there, but I don't want the background noise and distractions while I'm on the phone.
I spend the grocery money anyway. Getting gas knock offs is new and is atleast nice to see. If I spend $400 anyway, why not save $4..
Spending more on groceries JUST to save cents per gallon is pretty fucking smart.
I was able to get 15 cents off per gallon though last week so I made sure I was really empty and took a gas can with me too (for lawn equipment) in order to get it up to the 20 gallons. It was a lot of work for $3, but $3 is $3.
But to your point, if you can get food for less somewhere that doesn't have a rewards program and can use the Gas Buddy app to find gas for less somewhere else, that's the way to go. Someone could save $100 instead of $3.