Well, maybe $2 or $3, but I regard that as a worthwhile investment if it fixes the problem...., it shouldn't cost anything to try.
It could be (probably is) that other major brands have similar benefits. I'm only quoting what my brother has told me and he specifically mentioned Chevron. Before I purchased the Niro, I had a 2008 Honda CR-V and I always filled that with cheap gas from a non-Top-Tier station. Occasionally, it would misfire (never turned on the MIL light but it still caught my ear when it happened). When that started happening, I'd make a point to refuel at Chevron and the problem went away. Not sure if it was cause-and-effect or just coincidence, but I recall that sequence of events happening on at least three occasions.I don't see them as being better than any other major brand (almost all of which are similar tier one with some guaranteed level of detergent cleaning) and have seldom if ever bothered. I buy the cheapest, and use what is convenient or has the best points for using their brand.
In Indonesia, you can find people who have 1-gallon glass jugs of gasoline for sale in front of their house. I guess that works well for people driving mopeds (which seems to be the most common vehicle there). I didn't see that in England the one time I visited many years ago, but maybe they do that there too.In third world countries (which apparently includes Britain with their poor quality supermarket gas), what station you use may have more relevance, especially if you do not have a DI car like ours.