At our place we recently changed from the airport authority to Air BP supplying all the fuel.
The airport authority worked on the basis that we were never going to make a lot of money from G/A, and adjusted the landing fees and fuel prices to reflect the fact that 10 PA28s at £10 a landing is better than 0 PA28s at £15 per shot.
I'm pleased to say that Air BP adopt much the same policy, that said, avgas remains much the same price as petrol per litre, to reduce costs, they will shortly be installing a credit card self service pump on the G/A side of the airport.
Whatever you think about the cost of fuel, avgas at the majority of airports will be dispensed at hugely significantly reduced rate compared with jet fuel.
Storage costs, upkeep of bowsers, and staff costs for the supply of avgas are approximately 90% more for that of jet A1, almost exclusively due to the comparative volume of fuel supplied.
I can't see things improving at airports because of the overheads, and realistically things aren't going to get any better for the smaller airfields either.