If you've been playing in D2R for a long time, then you should know that to upgrade d2r items, you should first make the Horadric Cube recipe. The same goes for upgrading rare or unique items, which requires crafting a specific Horadric Cube recipe.
Unique items Each recipe is also different. But it always contains a perfect gem, except in the Hellforge where you can always get one, it doesn't drop on normal difficulty. They have a chance of randomly dropping from Act 1 of Nightmare for a chance to get a random Perfect Gem.
Upgrading a rare or unique Diablo 2 Resurrected Items For Sale will elevate the base weapon from Common to Superior, or from Superior to Elite. Therefore, its basic stats, such as damage and defense, will be improved. If those base stats are affected by percentage based modifiers, then upgrading does make a big difference.
RPGStash will give you the following recipe :
Rare Items (yellow)
Normal rare armor to Exceptional
Normal rare armor
Thul rune
Ral rune
Perfect Amethyst
Normal rare weapon to Exceptional
Normal rare weapon
Amn rune
Ort rune
Perfect Sapphire
Exceptional rare armor to Elite
Exceptional rare armor
Pul rune
Ko rune
Perfect Amethyst
Exceptional rare weapon to Elite
Exceptional rare weapon
Um rune
Fal rune
Perfect Sapphire
Unique Items (gold, which looks more like pale brown)
Normal unique armor to Exceptional
Normal unique armor
Shael rune
Tal rune
Perfect Diamond
Normal unique weapon to Exceptional
Normal unique weapon
Sol rune
Ral rune
Perfect Emerald
Exceptional unique armor to Elite
Exceptional unique armor
Lem rune
Ko rune
Perfect Diamond
Exceptional unique weapon to Elite
Exceptional unique weapon
Lum rune
Pul rune
Perfect Emerald
If you already know these recipes well and don't have time to collect them, then you can buy D2R Runes from RPGStash.com, which will be the most efficient way. Of course, you can also buy Cheap D2R Ladder Items directly, and you can also limit the quality attributes of items, which is very convenient for players. Order now and you will get Bonus XP +50% bonus.