Has an AFL game ever ended 123-36?
Exactly once. On August 26, 1911, Richmond beat St Kilda 123-36, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 123-36 in league history.
That makes 123-36 the 3883rd most common final score out of 6,649 that have ever occurred in AFL. One point away, 124-36 has happened never and 123-37 has happened never.