Has an AFL game ever ended 81-30?
Exactly once. On July 31, 1909, Carlton beat Melbourne 81-30, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 81-30 in league history.
That makes 81-30 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 82-30 has happened 1 times and 81-31 has happened 2 times.