Comment by Demon on Solo Leveling - Vol.2 Chapter 139

@Demon  you are so immature boy/girl. Why would you think that he will save a stranger who he doesn't even know much about. To save him, he had to give him one of the potion which is very rare. He only had 3 portion left as you may have already saw. So, would you have given someone a portion worth a life when you only have three left??

@Demon  Okay, let's say he saves the stranger first. What if he needs 3 elixir of life in the future? Will you get the purified blood of the demon monarch for him?

@Demon  I can't tell if you read the story wrong or you're just stupid

@Demon  You're the one who need to SYBAU

@Demon  bro he didn't trust him because according to his son he was an ass**** so what if he was lying then people all over the world will come to jinwoo besides he won't die he will just sleep forever

@Finn  
Honestly it's the author's fault for being incapable of doing math. 

In the chapter he crafted it in.  He made 6 (it literally said 6 were made). 

He used 1.  Then mysteriously 6-1 = 3.  Instead of 6-1 = 5. 

Sure.  They are miracle elixers that grant what's basically miracle levels of healing.  And are of Legendary Grade where each ingredient is of Legendary / Mythological Grade (He's lacking the Water Ingredient currently to make more). 

So ... yeah.  The rarity jumping up makes no sense.  (5 to 3.  Now 5 to 2).  

That said.  He still isn't obligated to use it for a stranger who could be utter garbage, and he was investigating since he knew Jack all about him.  That and with millions around the world with the same "Sleep Forever" Disease McGuffin.  It's not like he can just use it on everyone who exists that gets the disease.