I agree, that's how it should be and I'm happy to pay it. I don't even disagree with a small margin because it is a cash flow and that has costs.To be fair, delivery is a service and a chargeable one. We ourselves only charge what we get charged and don’t make a profit on it.
Unfortunately there are a lot of "look it's cheaper than the others" offers who then wham folk with a big delivery charge and whowee its the same or higher price. That to me is a con.