Strong Draught of Invigoration and Improved Draught of Invigoration result in the product

Hi, I noticed that these two endurance draguht potions both produce the same product (although with a different name) but the strong draught costs a significantly higher amount to make. Was this intented to have different values? They both produce 100 charges of the same level endurance regen buff and both of the regen buffs last for the same duration.