WoW Upgrades - The Item Upgrader
Upgrades will give you a boost to certain stats. Each upgrade boosts the level of an item by +3. Each upgrade also increases the random substatus.
Upgraded gear is generally more valuable, unless it has a low requirement by nature (like FB sorc shields) or has a high variance in stats (like eth Titan weapons). Upgrades aren't as useful for those with higher variance due to the need to roll an exact version.
Recycle Points
The item upgrader allows players to upgrade their gear by giving the currency to an NPC. Upgrades can be applied to any kind of weapon or armor. However, the item that is used to upgrade will remain in use for a long time and cannot be used again. Upgrades can be applied to enchantments.

The upgrader is located in all major cities, and can be accessed anytime to upgrade your equipment. It is recommended to visit the upgrader at least once every few weeks to ensure that your equipment is up-to-date.
Upgrades will cost more, based on the level of the item however, they are always cheaper than purchasing new equipment. For example upgrading a Benthic chest piece to 385 levels will cost 20 recycle points purchasing a similar piece from another player will cost 105.
Valorstones
Upgrades are items that can be used for weapon, armor, tool and accessory upgrades. They can be purchased by players from item upgrader NPCs in exchange for a variety of currencies, and can also be found in random treasure lists. Once purchased, an upgrade can be applied to any tool, weapon, or armor. button, which will display an image of the item when it is upgraded when the player has enough materials.
Upgrade costs differ based on the slot for the item and the current level of the item. For example weapons cost more than gloves, bracers, or bracers. Each step costs 15 Flightstones plus a specific number of crests. Certain upgrades provide a discount on the Flightstones. After an item has been upgraded to a certain amount it can be re-downgraded and sold to the upgrader at a lower cost.
Many locations offer item upgrader s, including the main Island and a few outposts. The NPCs provide an upgrade discount as well as a chance to obtain a new upgrade recipe. The discount for upgrading increases when more items are upgraded. It can be increased by having players finish certain achievements or quests.
Icewind Dale does not have an item upgrader at beginning, unlike Cromwell from Baldur's gate II. Instead the NPCs that are available to help with upgrades must be acquired through a variety of means that are both an improvement as well as a disadvantage.
In Season 3, the upgrade system was altered a bit, with some new features added. After a player has earned an upgrade to a specific item level for a particular armor slot, upgrading further items to the same level will cost less, even in the event that they belong to another set of gear.
The discount is available to all accounts. The amount of Harbinger Crests required to upgrade is reduced also, but is only available when certain milestones are reached.
Crests
When upgrading equipment in WoW players have a few choices. Flightstones are a currency that is available to all players for upgrading. Crests are more specific, and are used during specific item level upgrades. Crests are the main component of the Dragonflight gear progression system, which was introduced in 10.1, and come in 4 ranks.
The first thing to be aware of is that crests can only be used on equipment that is of a particular rank, and every rank has different requirements for its upgrade path. The most basic and straightforward upgrade route costs 15 crests while the most complicated requires as many as 20 crests depending on the type of gear being upgraded.
Players can obtain crests by working through content that is of the appropriate level, which involves walking around and engaging in outdoor activities for lower-tier gear, dungeons or raids of any difficulty for higher-tier items, or Mythic+ heroic raid bosses and dungeons to obtain endgame gear. These crests can be exchanged with an upgrader for the item, such as Cuzolth or Vaskarn in Valdrakken for the appropriate upgrade steps and paths.
The new currency system isn't too difficult to use, but it does bring some changes to the process of upgrading. When a piece of equipment attains the highest level of upgrade for any rank (Explorer or Adventurer), it no longer requires Flightstones. This allows players to upgrade their gear to the highest level possible on all of their characters, instead of relying on seasonal loot.
It's also crucial to choose crests in a wise manner, as they only have one use. For instance, it's best to make use of all your Whelpling-rank crests on the best gear you have available, and then save Drake and Wyrm crests to use for the next set of upgrades you're planning to create. This is especially relevant for items like trinkets and rings that fill multiple slots. The discount on the account will only apply when all slots on the character are filled with high-quality equipment.