Sell mini-passes that follow a theme at the same price (discuss) as the bigger passes. Not sure about how progression will work (discuss) but it would be cool as a sort of bigger bundle with pass progression mechanics.
E.g.:
The Royal Mini-Pass (royal themed outfits)
The Coffee Mini-Pass (espresso hat, barista outfit, coffee bean necklace or whatever)
The Gothic Mini-Pass (gothic themed outfits)
This would allow exploration of different cosmetic themes without the pressure of developing an entire pass. Perhaps don't give free tickets back for completing these so technically they're more expensive. (discuss - if there is a need for these to be more expensive)
One topic for discussion, how many tiers to these passes? I was thinking like 15-20 tiers. Perhaps these and the price can vary based on how many cosmetics were made based on the theme.