Some pumps would just go up to 99.9 cents a gallon. Shell tried to start pricing by the liter at some stations to try to save money on replacing the pumps.
I guess that lesson went unlearned. I recall when I was coming of age gas was typically around 0.99 but most billboards advertising the price had only space for a 1 in the dollar place, implying 1.99 as the highest price thought possible.