General

Potion buffs and ranges

Lately I've been watching some videos on youtube of boss solos and stuff and I see a lot of people using, besides their common buffs/party buffs/decent skills, buffs from potions. Like the ones you buy at npc and craft with alchemy. So my question is if are those potions really worth for bossing/training? And how much they increase your range? And, finally, what potions are those (their name) and where do I get them?

Thanks in advance!