I think the reality isn't top tier gas. Gas is gas. I would be more concerned with the age of the stations tanks and the volume they pump. I buy the cheapest gas I can find and have never, ever had a problem with bad gas. But I do choose the quality of the station pumping the gas.
Anyone who believes paying 25¢ a gallon more for gas because it's from a so called top tier supplier is only fooling themselves. But, it's their money and they can blow it anyway they wish, especially if it makes them feel good and gives them one thing less to worry about in life
Just reading the list of so called top tier suppliers is a joke. It includes just about every brand I've ever heard of other than Uncle Bob's Supper Fine Clean fuel from Podunk, Alabama. You would have a very difficult time even finding gas from anyone not on that list. Marketing is a wonderful thing!
Gas typically is delivered in bulk to one termal in most areas from one refinery where it's resold to distributors who sell it to the stations. Sure they love to tell you about all those "clean" additives they are selling you with their special high quality gas but does anyone really believe or trust an oil company to tell you the truth about anything they sell to you? I certainly don't.
Any vehicle with 250k miles on it is going to need injector work, that's life.