sakura
The problem with that is that it will cause devaluation in the same way, it will not raise the price of junk stones, because fashion points are "farmed" passively, simply by being in the game, so I just have to have 50 fashion points, buy a box, get a junk stone and clone a stone that would have cost me 20-30-50-100m to buy.
The gacha system is what gives them value. If we make it easier to obtain them we will only irreparably harm a market that mainly favors new players.
Also, people who want to have several costumes with the stones in all of them are usually people who have already finished their equipment, and have nowhere to spend their zeny and just see how it accumulates, so they spend it on costumes and stones for themselves, and make their characters pretty and functional. And even if you already have your gear ready, but you're not a zeny hoarder and you want to do this, it will give you a reason to farm and be active in the game, instead of just sit down on Prontera and wherever you want.
Even if you don't have your equipment ready and you want to do this, you will have to analyze and establish your priorities. It is part of the economy and planning of each person.