Not unheard of.
Just experienced it for West Coast - VCE. Booked at 135k one way for business AAnytime. Looked again this week out of curiosity- now at 300k one way AAnytime. More than double! For shoulder season to boot, not even true “summer peak”.
That’s said....... Saw some decent milesaver availability in economy for the same routing. And on AA metal across the pond, so no YQ charges!