I have been maining 
for the second half of the season and I love it. My starters are 
and 
. The game recommends upgrading the potion to a 
, but I have never done it. It seems ineffective to spend gold to get less heal and a small mana boost... Can someone make a case why I should spend my hard earned gold on a instead of getting 
or building towards 
?
It's not less heal. Hunters holds 5 charges while refillable holds only 2. 5 stacks of hunters gives you way more health than two stacks of refillable. Equally importantly it gives you mana which is a god send for blue buff dependant junglers. This isn't even factoring in that the hunters potion refills one charge per camp you clear. Building hunters potion let's me effectively farm without starving my mid laner of blue buff
Skarner doesn't need Hunter's Potion. His shrines provide mana regeneration while his shield and jungle item will suffice for mana regeneration.
Farming. You get a stack every time you kill a large monster. Basically, you'll never really have to buy another potion and the gold will pay for itself. Endless sustain and clear basically.
I tend to get it when I play with 4 randoms when I jungle and everyone knows in solo Q every lane needs a gank 24/7 cause their garbage. So if I'm low hp or mana I pop 3-5 Potions before I gank so when I'm like 500 hp I can be 800 Hp while the potions are ticking.
It also helps after ganks to heal back up and keep on farming in jungle as you get 1 extra for each camp.
This item is really strong on champions such as 
as they tend to counter jungle to make the extra potion per camp work better and while farming 24/7.
it means you can hyper farm and not have to worry about backing for more potions.
if you dont normally buy potions after your first or second back, you dont get this item.
it is however useful for staying topped off between camps and staying healthy for a gank. its just usually more important to have that extra 10 ad longsword or 15 ar cloth armor. and just generally buying a completed item sooner.
good for champions that have low sustain and are mana reliant, like 
I can't say for since I don't play him at all but usually you get the hunter potion if you have terrible/bad sustain in the jungle, are not planning to rush life steal and can't afford to smite every camp to minimize the damage taken.
On my normal rooster I only get it on 
since he lacks the sustain to stay healthy on the jungle until quite late and you need your smite to gank so you can stick to your targets. Mana hungry champions like can be managed by using your abilities less rashly and just resignate to slower clears, then go hit the crab and get all your HP back. Wukong however will kiss the crab too fast to regenerate enough HP to compensate so... I help him with a potion
Not every recommended item is optimal.
skarner specifically doesn't need hunters, but it works on champs that have a weak early clear
Only time I ever made the potion was when I forgot smite.
