WoW Upgrades - The Item Upgrader
Upgrades will give you a boost to specific stats. Each upgrade increases the level of an item by +3. Each upgrade also boosts the random substatus.
The more modernized gear generally has a more value in trade as long as it meets low requirements (like the FB shield of the sorc) or a very high stat variation (like the eth titan weapons). Upgrades aren't as useful for those with lower requirements due to the need to roll an exact version.
Recycle Points
The upgrader for items allows players to upgrade their gear to a higher level by providing the appropriate currency to the NPC. Upgrades can be applied to any kind of weapon or armor. The item used to upgrade the item will be consumed and can't be used again. Upgrades can be used to create Enchantments.
The upgrader can be found in all major cities, and is accessible anytime to upgrade your gear. It is recommended that you visit the upgrader every few weeks to ensure that your equipment is up to date.
The cost of upgrades will depend on the current level of the item being upgraded but they will always be less expensive than buying new equipment from other sources. For instance, upgrading a Benthic chest piece to 385 ilvl will cost 20 recycle points, while purchasing the same item from a different player will cost 105.
Valorstones
Upgrades are items that can be used to purchase tools, armor, weapon, and accessory upgrades. They are purchased by players through item upgrader NPCs in exchange for different currencies, and can be found in random treasure lists. Once an upgrade is purchased, it can be used on any weapon or tool with the help of The button will display the item's next upgrade level, when there are enough materials.
The cost of upgrading varies based on the item slot, and the current item level. For example, weapons will cost more than bracers, or gloves. Each upgrade costs 15 Flightstones plus a certain number of crests. Some upgrades give discounts on Flightstones. Once an item is upgraded to a certain degree it can be re-downgraded and sold to the upgrader at a lower cost.
Upgraders for items can be found in a variety of locations on the main island and some outposts. The NPCs offer an upgrade coupon and a chance to obtain an entirely new recipe. The discount for upgrading increases as more items are upgraded. It can also be increased by having players complete certain achievements or quests.
Contrary to Cromwell in Baldur's Gate II, there is no upgrader for items available at the start of Icewind Dale. Instead, the NPCs that are available to help with upgrades are acquired via several methods that are both an improvement as well as a disadvantage.

In Season 3, the upgrade system has been modified a bit, and several new features added. After a player has earned an upgrade to a particular item level for a particular armor slot, upgrading other items to that same item level will cost less, even when they belong to a different gear set.
The amount of Valorstones needed for upgrades is decreased, and the discount is affixed to all accounts. The amount of Harbinger Crests required to upgrade is reduced also, but is only available after certain milestones are reached.
Crests
When upgrading gear in WoW, players have a couple of 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 a crucial component of the Dragonflight Gear Progression System, which was introduced in version 10.1. upgrade item come in four ranks.
The first thing to be aware of is that crests can only be used on equipment that is of a particular rank, and that each rank has different requirements for its upgrade path. The simplest and simplest upgrade is 15 crests. The most complex upgrade requires up to 20 crests, depending on the kind of equipment that is being upgraded.
Players can earn crests through working through content that is of the appropriate level, which means walking around and doing outdoor activities for gear of lower tiers, raids or dungeons of all difficulties for higher-tier items or Mythic+ heroic raid bosses and dungeons for endgame gear. Crests can be exchanged at an upgrader NPC like Cuzolth in Dornogal, or Vaskarn in Valdrakken to get the appropriate upgrade paths and steps.
The new currency system isn't complicated to use, but it brings some changes to the process of upgrading. When a piece has reached the highest level of upgrade for any rank (Explorer or Adventurer), it is no longer required to purchase Flightstones. This is to allow players to get their gear up to the highest level possible on all their characters, instead of relying only on seasonal loot.
It's also important to use crests with care, since they are only used for one purpose. It is recommended to put your Whelpling-rank Crests on the highest-quality gear you can find, and keep Drake and Wyrm Crests to be used for the next set of upgrades. This is particularly applicable to rings and trinkets that take up multiple slots on the character, which can only be eligible to avail the account-wide discount if all slots are filled with high-quality gear.