The reason they had to do that was because the British started bitching when they gave it away for free. The British Red Cross was charging their troops so the American Red Cross was force to do it so British Morale would not be hurt.
My father also did not like to have to pay for things from the Red Cross during WWII. At least the doughnut dollies did leave compounds and go to a few LZ's during Vietnam. Of course some of these girls along with other women in Vietnam went home rich. So apparently they charged for everything in addition to the donuts. But on the other hand, they weren't back in the States burning American flags with their draft dodging current boy friends.