Let the ATM fee be the current cost of moving digits and paper plus the cost of payments to cover past bit error losses.
The cost of moving paper and digits cannot be more than a half point when price variation is less than 5%. Then the assumption of zero transaction costs go away, we all do triple entry accounting. We don't, we back put the cost of past losses, a whoops, we know about them. Add in Roger's death discovery, and bingo, we see the problem, insurance failure.