Well the math is pretty simple.. Stormscale is priced based on the Gravenscale armbands (because that is what we are using it to craft) and it’s like this.
1 Armband = 150 Leathers . Meaning that 1 Leather = 1/150 Armbands OR 1 Leather = 0.00666666666666 Armbands. So pretty much… 1 Leather is 0.0066 x 100 = 0.66% of the Price of the Armband.
Your math here is incomplete. You’re multiplying 0.66% against the price of obliterum, when really, an armband only nets you about 25 Ash, so your multiplier is about 4* too high.
It should be ~ 0.1666% of an Oblit.