So just a curiosity but I am sure items in the store are pure gross when players buy them on credits or through purchasing REX

Have you ever considered a progression price scale starting at Classic and bellcurving into SFP?

making older items like cosmetics, premium recipes (which probably wont ever sell again anyway now that they are outmodded and should probably be added to trainers now) Mounts, Equips, Pets, Pet Skins (which could be a huge profit pool were you to make all existing pet skins buyable and add more of the vast pool of open world mobs as new skins, maybe allow some of the current skins to be used by more than one class etc.), old relic lock boxes with current loot tables to match the value they get priced for, dimension items, rift ZE lures (maybe add more of the rare hard to get onesto the inventory)

just a hand full of ideas more obvious to my point of perspective, I am sure others might have ideas to add as well