You took the words out of my mouth.
I have many brides shocked at the cost of so called dummy cakes. While you can save a small amount of money, you are correct. For dummy cakes, the only money you are saving is the cost of the cake, ingredients inside, the baking time. But the dummy still costs money too and the work to decorate it is the same. Still using the same material to cover it as well…so the difference overall is minimal.
Most people just don’t see that though.