SHAEF ordered the ARC to charge for their services since the British RC could not afford to give their services for free. It was a wartime measure to preserve Tommy morale, reducing already building resentment against US GIs.
Of course, high level command desicions don't make as good a story as barracks room grousing.
Exact same story I got from my father, he still did not appreciate paying for the coffee and donuts.
" SHAEF ordered the ARC"
Funny how out of 11 men that part never made it to light.