Free version for those with verified low income?

(I've been toying with models like this for awhile, and not to say its an easy or simple solution to implement, especially when considering bad actors, but it seems the best chance at getting something "fair")

Alternatively could steal from games and add "cosmetics". Charge extra for things like themes that personalize but don't necessarily improve the experience. Items with enough value that people will "want" it but not "need" it.