I spent $180 boosting my character (bard, because white mage is too boring), skipping Heavensward for Stormblood, and resubbing. Sad CAD killer conversion.
I play this game for 30 minutes a week and I'm still level 61! At least bard really is more interesting than white mage. Done worse though--I bought $100 worth of Hearthstone cards for the Un'goro expansion and played like 4 games that season.