Ok I'll bite: this is a weird comparison. Surely the 5 (!) insulated bags are the bulk of the weight? Those ones aren't fungible with disposable bags, which do

Ok I'll bite: this is a weird comparison. Surely the 5 (!) insulated bags are the bulk of the weight? Those ones aren't fungible with disposable bags, which don't insulate. The weight in the car is also an irrelevancy, because just tire pressure will absolutely swamp the difference, by which I mean there would be no way to extract the cost from the noise no matter how hard you tried.