Has an AFL game ever ended 81-54?
Exactly once. On April 16, 2011, Geelong beat Sydney 81-54, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 81-54 in league history.
That makes 81-54 the 3883rd most common final score out of 6,649 that have ever occurred in AFL. One point away, 82-54 has happened 1 times and 81-55 has happened 3 times.