Then there was the dreaded mehrwertsteuer, the German equivalent of VAT. For airmen, this was administered by the PSI, who nominally made/ legalised the tax-free purchase, and debited the airman. Known as a "murgatroyd" by those who found the language challenging.
Officers worked through the Mess, and paid [or defaulted] on their mess bills.
Lets see: Schrank, set of chairs, corner seating unit, top of the range camera and full set of lenses, ornate lamps, clothing. Drink, kassler, cheeses ......
The lawnmower and the Weber [both still going strong] were via the PX, the peanut butter from the Maple Leaf.
Army garrison towns such as Detmold were very very anti accepting such tax-free business until it was explained that "this is by an RAF mess". My wife still has the loden overcoats.