Has an AFL game ever ended 79-30?
Exactly once. On September 8, 2018, GWS beat Sydney 79-30, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 79-30 in league history.
That makes 79-30 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 80-30 has happened never and 79-31 has happened 1 times.