Magical: Rare: Set: Unique: Crafted: Honorific: Socketed item + Oil of Disjunction -> separate item. These recipes separate the socket fillers (gems, jewels, runes) from an item and return both the item and the socket fillers. Borgin's Vigil cannot be duped because, well, there is only one Borgin.
Later on, sell rare (yellow) items to get profit. Yes, the fastest way is to socket a rune into throwing weapon and sell it to any vendor. +3-6 to Summon Shadows), then the bonus is an 'oskill', giving this skill to any class for free Oskills If an item has a skill bonus with no character class requirement (eg. The stats of each unique depend on the tier of the base item: higher tier versions of the same unique are improved in all aspects, but have higher requirements
Each regular item has one unique version that can drop anywhere in the game. Home Median xl unsocket unique Tiered Uniques :: Median XL / Game Guid