Its best to rely on subscribtion based mmo instead of p2w, give chance of certain really good fluff items you can only get by tokens in the plus subscribtion. Would make plus worth a lot same time not affect game play for f2p players. Means you would get good income and same time get populated game with high reveneue. Kinda like elder scrolls online system mixed with cash shop system in wow but token subscribtions. Random loot boxes allmost everyone hate even if p2w

Remove stats for costumes, introduce new token system you get with daily 14 day subscribtion, tokens where you can use to customize your own outfits

Special character appearances should also be possible with these tokens. This would appeal to a large crowd without affecting game play

The more advanced customization the more tokens would be necessary, and then have half year fashion changes to keep interrest up and people keep subscribing

Like in life it costs to look good while rest you just need hard work

For every season you can have a fashion week by player designers, those that like what they see can bid on their outfit with tokens

Fashion week design should only be possible through preliminary outfit that players can bid on with tokens they recieved through subscribtion, the tokens the designer gets she can make name for herself and make non fashion week costumes marked with her name in market place for silver

Fashion week you get max amounts of designes to make and only a design can only be bought by one buyer with token bids

One outfit per design branded name like "channelle" for each bid winner

Make own brand in a outfit, that special really talented designer.

Tatoo contests, hair dressing contest and what not

Make it worth keep subscribing for stocking up those tokens for bragging costumes

You can call player made fashion week vanity week if you like :P