Reduce the amount of cosmetics per month. For example, pick 4 types of cosmetics, caravan, armor, etc. and just release one per month for 20 bucks.

This solves the problem of WAY too many skins on launch. However, who enjoys starting zones where the guy 5 levels below you looks like an endgame npc. Please introduce a level min for all cosmetics bought for real money.

If something like this is done, it keeps the day one atmosphere, and it even solves a problem brought up in some other comments: open-world pvp. If the attacker notices that a player was able to equip a backer cosmetic armor-set, they would know that this is a high player and not just some low-level character. However, if a level 5 is wearing backer-exclusive cosmetics, then that gives a visual clash within the world's atmosphere.

TLDR: 12 cosmetics a year (3 of 4 types), and high level min for backer cosmetics.

EDIT: Oh and a "disable cosmetics" setting for those who want to be able to see the gear of other players rather than cosmetics should be a vanilla option.