WoW Upgrades - The Item Upgrader
Upgrades provide a guaranteed boost to specific stats. Each upgrade boosts the level of an item by +3. Each upgrade also boosts the random substatus.
The upgraded gear is usually 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). The latter are less valuable from upgrading due to the necessity to roll for a perfect model.
Recycle Points
The item upgrader lets players upgrade their gear by offering the currency to an NPC. Upgrades can be applied to any kind of armor or weapon. The item used to upgrade the item is discarded and cannot be used again. Upgrades can be applied to the enchantments.
You can upgrade your gear anytime by visiting the upgrader in any major city. It is recommended to visit the upgrader at least once every few weeks to ensure that your equipment is up-to-date.
The cost of upgrades will vary based on the current item level of the item being upgraded however, they will always be less expensive than buying new gear from other sources. Upgrades such as upgrading a Benthic chest up to ilvl385 will cost you 20 recycle points. A similar item will cost you 105.
Valorstones
Upgrades are items that can be used to improve the quality of weapons tools, armor, and other items. They can be bought by players from NPCs who sell upgrades for items in exchange for a variety of currencies, and may also be found in random treasure lists. Once item upgrading is purchased, it can be applied to any weapon, tool, or armor using a The button will display a preview of an item's next upgrade level in the event that there are enough materials.
Upgrade costs differ based on the slot for the item and the current level of the item. For instance weapons are more expensive than gloves, bracers, or bracers. Each upgrade 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 level, it can be downgraded and sold to the upgrader for a lower price.
Upgraders for items are available at many locations on the main island as well as some outposts. The NPCs offer both an upgrade discount and the chance to get a brand new upgrade recipe. The discount on upgrades increases when more items are upgraded. It can be increased if players complete certain achievements or quests.
Icewind Dale does not have an item upgrader at beginning unlike Cromwell from Baldur's Gate II. The NPCs who are able to facilitate upgrades are only available through a variety means. This is both a positive and a disadvantage.
In Season 3 the upgrade system was tweaked a bit, with some new features added. After a player has upgraded to a certain item level for an armor slot, upgrading other items to the same level, will cost less. This is true regardless of whether the items come from another set of gear.
The amount of Valorstones required for upgrades is decreased, and the discount is available across all accounts. The amount of Harbinger Crests required to upgrade is reduced as well, but is only available once certain milestones are achieved.

Crests
Players have a variety of options when it comes to upgrading their gear in WoW. Flightstones are an option that is accessible to all players for upgrading. Crests are more specific and are used for specific level upgrades for items. Crests are an important part of the Dragonflight Gear Progression System that was introduced in version 10.1. They are available in four ranks.
First, you should know that the crests can only be purchased for equipment with a certain rank. Each rank has an upgrade path that is different. The simplest and easiest upgrade is 15 crests. The most complex upgrade could require as much as 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, whether that involves walking around and engaging in outdoor activities for gear of lower tiers, dungeons or raids of all difficulties for higher-tier items or Mythic+ heroic raid bosses and dungeons to obtain endgame gear. These crests can then be exchanged at an upgrader NPC, like Cuzolth in Dornogal, or Vaskarn in Valdrakken to obtain the appropriate upgrade paths and steps.
Utilizing these new currencies isn't too complicated, but the system will introduce a few changes to the overall upgrade process. For instance, once a piece of equipment reaches the highest level of upgrading for any rank (Explorer, Adventurer, Veteran, Champion, Hero, or Mythic) it won't need Flightstones to be upgraded. This is to allow players to upgrade their equipment to the highest possible ilvl for all their characters instead of relying on seasonal loot.
It's also essential to use 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 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 rings and trinkets that occupy several slots. The account-wide discount will only apply when all the slots on the character are filled with high-quality gear.