WoW Upgrades - The Item Upgrader
Upgrades give a guaranteed boost to certain stats. Each upgrade boosts the item level by +3. Each upgrade also boosts the random substatus.
Upgraded gear generally sees greater value for trade, unless it has inherently low requirements (like the FB shield of the sorc) or very high stat variance (like eth titan weapons). The latter are less valuable from upgrading due to the necessity to roll for a perfect model.
Recycle Points
The item upgrader allows players to upgrade gear to a higher item level by supplying the appropriate currency to the NPC. Upgrades can be applied to any kind of armor or weapon. 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 every major city, and can be visited anytime to upgrade your equipment. It is recommended to visit the upgrader every few weeks to ensure that your equipment is up to date.
Upgrades can cost more based on the level of the item, however they'll always be cheaper than purchasing new equipment. Upgrades such as upgrading a Benthic chest up to the level of ilvl385 will cost you 20 recycle points. Buying a similar item will cost you 105.
Valorstones
Upgrades are functional items that can be used to upgrade weapons, tools, armor, and accessories. They are purchased by players through NPCs that sell upgrades to items in exchange for various currencies, and can also be found in random treasure lists. Once purchased, an upgrade can be applied to any weapon, tool, or armor. The button will display a preview of an item's next upgrade level, when there are enough materials.
The cost of upgrades varies based on the item slot and the current item level as well as the level of the weapon, which is more than bracers or gloves, for instance. Each upgrade costs 15 Flightstones and a number of crests, with some upgrades offering discounts to lower the cost of Flightstones or crests that are used. After an item has been upgraded to a certain degree and is degraded, it can be sold and returned to the upgrader for a lower amount of the two currencies.
Upgraders for items are available at many locations on the main island and some outposts. The NPCs offer an upgrade coupon and the possibility of obtaining an entirely new recipe. The upgrade discount increases depending on the amount of items being upgraded. It is also possible to be increased by having players complete specific achievements or complete quests.
Unlike Cromwell in Baldur's Gate II is no upgrader for items at the start of Icewind Dale. Instead, the NPCs that are available to help with upgrades must be acquired through various methods that are both an improvement but also a drawback.
In Season 3, many new features have been added to the upgrade system. After the player has upgraded to a certain level of item for an armor slot, upgrading other items to the same level will cost less. This is even if the items are from another set of equipment.
The amount of Valorstones needed to upgrade is reduced and the discount is account-wide. The amount of Harbinger Crests needed for upgrades is reduced too, but it is only available once certain milestones have been reached.
Crests

When upgrading gear in WoW, players have a couple of options. They can make use of Flightstones which are a general upgrade currency that is accessible to everyone, or crests, which are more specialized and are used to upgrade specific levels of the item. Crests are an integral component of the Dragonflight Gear Progression System introduced in version 10.1. They are available in four ranks.
The first thing to note is that crests can only be spent on gear of a specific rank, and that every rank has different requirements for its upgrade path. The easiest and most straightforward upgrade costs 15 crests. The most complex upgrade can require up to 20 crests, contingent on the type or gear that is being upgraded.
Players can earn crests through working through content at the appropriate level. This could mean engaging in outdoor activities or completing dungeons and raids in all difficulty levels to obtain equipment of lower tier or Mythicbosses for raids, or dungeons that have a high difficulty for endgame gear. The crests can then be exchanged with an upgrader, such as Cuzolth or Vaskarn, in Valdrakken to upgrade the item in the proper steps and pathways.
The new currency system isn't difficult to use, but it brings some modifications to the upgrade process. For instance, when an item is at the highest level of upgrade for any rank (Explorer, Adventurer, Veteran, Champion, Hero, or Mythic), it won't require Flightstones to be upgraded. This is to allow players to get their equipment up to the highest possible ilvl on all their characters rather than relying solely on seasonal loot.
Another important modification is that crests have one usage therefore it's essential to use them properly. For instance it's best to utilize all of your Whelpling rank crests on the best equipment available, and then keep Drake and Wyrm crests to use for the next set of upgrades you're planning to create. item upgrades is especially applicable to items like trinkets and rings that take up several slots. The discount on the account will only apply when all slots on the character are filled with top-quality equipment.