Quality Items

Can someone please explain to me the Point or Difference Between the Quality of items?
I understand certain ones such as potion, better quality equals more Health/Stats etc.

But with Certain things I dont get it? Like Herbs or Items needed for crafting that give no stats.

For Instance, like I am going to have a guildie craft the Elemental Lariat Neck. So when buying mats required, do I really need to open the bank for the Higher Quality mats? Whats the Benefit?

Potion Absorption Inhibitor, all ranks say it increases Pots by 50%. So what is the benefit of buying rank 1 vers rank3?

So quality for non consumables affects your skill level when crafting.

So for instance if you want to make a level 3 potion of whatever, and you don’t have enough skill points to make it gold quality with bronze quality mats, you can add better quality ingredients and it will boost your skill.

I think it’s around 25% more skill for the next tier of mats, but I could be wrong with the exact amount.