Fractal weapons
I would not want to see those weapons on the trading post; the entire point of those are to be a reward for the players who get to the higher levels of Fractals.
However, I agree that they are extremely rare and that having them up to RNG can be a pain. You could make them available for pristine relics but, make it so that the shop tab with the fractal skins is only available if your Personal Reward Level is high enough for Fractal weapons (26 or higher). This will avoid farming of lower level fractals for relics and the creation of another “currency”.
While we are on the subject of Fractal weapons, they should be weapons with full stats or skins. Not a weapon that you need to transmute for it to be useful.
I honestly feel the drop rate is about 50% at 40+ which is pretty decent although you’re right about getting the one you want. That’s much harder.
Also, you can salvage or mystic forge the fractal weapons…