As many clubs do in the more southern parts of Europe, one could prob90 get cheaper avgas by importing it in 200 litre drums.
Of course this causes the airfield-based avgas facility to close, but that is OK for the "I am allright Jack" subsection of the GA "community"
I don't think 421C was referring to the normal margins that Filling Stations at regional airports are making. The airport operator can obviously use the filling facility as a source of extra income : that is what many "Syndicats d'Initiative - Bureaux de Tourisme" in France do, as a contribution to facility maintenance. And, because they are the
only operator at the airport, they can get away with an extra 10-20 cents per litre (or about $1 / gallon).
However, you could then buy yourself an airstrip or get fuel concessions at a larger regional airport (e.g. through an FBO delivering avgas in competing with the existing fuel station). IF there is a price gap, it would lead to prices going down or your FBO turning a lot more volume. We are not talking about 200 liter drum & hand pump operations like in central Brazil or something; Rather, you would source 5000-20000 litres avgas at a time and market your airfield as a refuelling hub*. There is absolutely no incentive to restrict deliveries to local based aircraft. Quite the contrary.
I'm thinking typical transit airfields like Haverfordwest, Southend, Merville, Limoges, Augsburg, Kiel, Trier etc... for such an operation, so that the landing fee would be competitive and earned back by discounting say €0.30 / £0.25 per litre. One could also supply individual flying clubs and FBO's, acting as a wholesaler / reseller.
Of course all this DOESN'T work if EVERY industry supplier charges the same large Avgas / Jet-A1 spread.
*If anyone starts moaning about planning commissions in the UK and the impossibility to get a fuel station implanted, I will call them names.
