WoW Upgrades - The Item Upgrader
Upgrades can give you boosts in specific stats. Each upgrade increases item level by +3. Each upgrade also increases a random substat.
The upgraded gear typically has a higher trade value regardless of whether it has low requirements (like the FB shield of the sorc) or a very high stat variation (like the eth titan weapons). The latter are less valuable from upgrading due to the necessity to roll for a perfect version.
Recycle Points
The item upgrader enables players to upgrade their gear to a higher 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 cannot be used again. Upgrades can be applied to Enchantments.
The upgrader is located in every major city, and is accessible anytime to upgrade your gear. To keep your gear up-to-date, it is recommended that you visit the upgrader each several weeks.
Upgrades can cost more based on the level of the item however they'll always be cheaper than purchasing new equipment. For example upgrading a chest piece from Benthic to 385 ilvl will cost 20 recycle points, purchasing a similar piece from a different player will cost 105.
Valorstones
Upgrades are items that are used to improve the quality of weapons and tools, armor and accessories. They can be purchased from item upgraders NPCs in a variety of currencies. They can also find them in random treasure lists. Once purchased, an upgrade can be used on any tool, weapon or armor. The button will show the item's next level of upgrade, in the event that there are enough materials.
The upgrade cost depends on the slot of the item and the current level of the item and the weapon's price is higher than gloves or bracers for instance. Each upgrade costs 15 Flightstones and a few crests, with some upgrades having a discount to reduce the cost of Flightstones or crests used. Once an item is upgraded to a certain amount it is able to be downgraded and sold to the upgrader at a lower cost.
Many locations offer item upgrade rs in addition to the main island and some outposts. The NPCs offer both an upgrade discount as well as a chance to get a brand new upgrade recipe. The upgrade discount increases depending on the amount of items that are being upgraded, and can be increased by requiring players to complete specific achievements or quests.
Contrary to Cromwell in Baldur's Gate II, there is no upgrader for items at the start of Icewind Dale. Instead the NPCs that can be used to upgrade require several methods, which is both an improvement and a drawback.
In Season 3 the upgrade system has been modified a bit, and some new features added. After a player has earned an upgrade to a particular item level for a particular armor slot, upgrading additional items to that level will cost less even when they are part of an entirely different set of gear.
The discount applies to all accounts. The amount of Harbinger Crests required to upgrade is reduced also, but is only available once certain milestones are reached.
Crests

When it comes to upgrading gear in WoW players have a variety of options. They can use Flightstones which are a common upgrade currency available to everyone players, or crests that are more specialized and are consumed during upgrades at specific levels of items. Crests are a crucial element of the Dragonflight Gear Progression System introduced in version 10.1. They come in four ranks.
First, you should know that the crests can only be purchased for equipment of a certain rank. Each rank comes with distinct upgrade paths. The simplest and most straightforward upgrade route costs 15 crests while the most complicated can require as much as 20 crests, based on the type of gear being upgraded.
Players can earn crests through finishing tasks at the appropriate level. This could mean doing outdoor activities or completing dungeons and raids in any difficulty to earn equipment of lower tier or Mythicbosses for raids, or dungeons with heroic difficulty for gear in the endgame. 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 routes.
The new currency system isn't complicated to use, but it will bring some changes to the upgrade process. When a piece of equipment reaches the highest level of upgrade for any rank (Explorer or Adventurer) it is no longer required to purchase Flightstones. This change is intended to allow players to upgrade their equipment to the highest ilvl possible for all their characters instead of relying only on seasonal loot.
Another notable change is that crests have one purpose, so it's important to use them properly. For instance, it's a good idea to make use of all your Whelpling-rank crests on the best gear you have available, and then save Drake and Wyrm crests for the next batch of upgrades you plan to create. This is especially relevant for items like trinkets and rings that fill several slots. The account-wide discount will only be applicable if all slots on the character are filled with high-quality gear.