Farming Elevation Cubes

[frapucino]

Anyone has any suggestion on how to farm Elevation Cubes without buying them on Trading House???
I have opened over 30 random boxes from S-grade Mercernary missions and those from running LB floors (crafting at Blacksmith).
I have not managed to get even 1 of Elevation Cube.

I want to upgrade my Genesis Earring but I do not have much money to buy Elevation Cubes on Trading House.

Thx & rdgs,

[Jeezus]

Elevation cube was originally a Rare item
but cherrycredits gave away 1 elevation per char during their last days of service in august 2017 so price went really down that time and now again getting costly slowly
dont really have much choices now , better farm gold and buy cheap in TH

Elevation Cube from
Unique Remote dungeon box = 0.04% Chance
Epic Remote dungeon box = 0.05% Chance
Purified Labyrinth Relic box = 0.1% Chance
Gold Chest select Labyrinth = 0.1% Chance
Gold Chest select Rune dragon 4 man = 0.5% Chance
Lagendia Exploration Big Chest = 0.1% Chance