"I used to be an adventurer like you.
And as you well know, adventure brings you tons of effective potions.
Everytime you get 'em you keep 'em safe, waiting for the very dangerous and critical moment for 'em to be used well.
That's how I ended up actually drinking none of 'em and gathered so many potions enough to set up a shop!
However, looking back on my time of being an adventurer, there was not a single reason to buy potions which you can rake from literally everywhere and already jam-packed inside your backpack.
You see, this place is slack all day long.
Now I'm in the same box with those merchants whom I ignored all along.
I'm even getting tired and angry of looking these damned colorful bottles of magical draught.
Sorry for the long wind! Sometimes it's so hard to keep my temper. Now, what do you want young fellow?"
"I wanna sell potions."