The station I referred to isn't the only one with that $1 difference. It just happens to be in our small town and I was willing to give them business. The standard pricing is generally 25-30c for mid-grade and 50-60c for premium. I do remember when grades were in $0.10 increments !I have heard of the huge price difference between regular and premium. Here premium is only $.30-$.40 more.
Is @GoldDot40 still around ? He's a fuel tanker driver and as I recall, he says that "no way in hell" would that happen, no matter how much the station owner tried to bribe the tanker driver.However, if you are dealing with "Mom & Pop" type stores, that is likely the issue. Independents can intentionally over order the 87 octane, and have the driver drop the amount that won't fit into the premium tank(s).
It's been this way for years.