The Seller(s) of Weaker Potions

The weaker potion seller is claimed to exist by the potion seller. It is assumed that the weaker seller will have potions suitable for men rather than beasts and dragons.

The Potion Seller uses the phrase " a  weaker potion seller". An actual weaker potion seller may not even exist, The Potion Seller just assumes there is a weaker potion seller.