the original source - The Item Upgrader
Upgrades give a guaranteed boost to certain stats. Each upgrade increases item level by 3. A random extra substat is also boosted alongside every upgrade.
Upgraded gear is generally more valuable, unless the item has a low requirement by nature (like FB sorc shields) or has a large variance in stats (like Eth Titan weapons). The latter see less value from upgrading due to the necessity to roll for a perfect model.
Recycle Points
The item upgrader enables players to upgrade gear to a higher level by supplying the appropriate currency to the NPC. Upgrades can be made on any type of weapon or armor. The item used to upgrade the item will be consumed and can't be used again. Upgrades can be applied to the enchantments.
The upgrader is located in all major cities and can be accessed anytime to upgrade your equipment. To ensure that your equipment is up-to-date it is recommended that you visit the upgrader each few weeks.
The cost of upgrading will be based on the current level of the equipment being upgraded but they will always be cheaper than purchasing new gear from other sources. For instance, upgrading a Benthic chest piece to ilvl 385 will cost 20 recycle points while purchasing the same item from another player will costs 105.
Valorstones
Upgrades are items that can be used to purchase weapons, armor, tools, and accessory upgrades. They can be bought by players from NPCs that sell upgrades to items in exchange for various currencies, and may also be found in random treasure lists. Once an upgrade has been purchased it can be applied to any weapon or tool with an The button will show the item's next upgrade level in the event that there are enough materials.
The upgrade cost depends on the item slot and the current level of the item as well as the level of the weapon, which is more than gloves or bracers for example. Each upgrade costs 15 Flightstones and a variety of crests, with certain upgrades having a discount to reduce the cost of the Flightstones or crests that are used. Once an item has been upgraded to a certain amount and is degraded, it can be sold and sold back to the upgrader for a lesser amount of both currency types.
A lot of locations offer upgraders for items which include the main island and some outposts. The NPCs offer both an upgrade coupon as well as the possibility of getting the latest recipe. The discount on upgrades increases as more items are upgraded. It can be increased if players finish certain achievements or quests.
Unlike Cromwell in Baldur's Gate II there is no upgrader for items available at the beginning of Icewind Dale. The NPCs who can facilitate upgrades are available only through a variety of methods. This is both a benefit and a drawback.
In Season 3 the upgrade system has been modified a bit, and numerous new features added. 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 those items are from an entirely different set of equipment.
The amount of Valorstones needed to upgrade is reduced and the discount is account-wide. The amount of Harbinger Crests required for upgrades is reduced also, but is only available once certain milestones are reached.
Crests
When it comes to upgrading equipment in WoW, players have a few options. Flightstones are a currency that is available to all players for upgrading. Crests are more specific and are used for specific item level upgrades. Crests are an essential part of the Dragonflight gear progression system introduced in 10.1 and are available in 4 ranks.
First, you must be aware that the crests can only be purchased for equipment of a certain rank. Each rank comes with distinct upgrade paths. The most basic and straightforward upgrade route costs 15 crests while the more complex one may require as many as 20 crests, based on the type of gear being upgraded.
Players can earn crests by finishing content at the appropriate level. This could be done by engaging in outdoor activities or taking on dungeons and raids of all difficulties to get lower-level gear or Mythicbosses of raids or dungeons that have a high difficulty for endgame gear. Crests can be exchanged at an upgrader NPC like Cuzolth in Dornogal, or Vaskarn in Valdrakken, for the appropriate upgrade pathways and steps.
The new currency system isn't difficult to use, but it brings some modifications to the upgrade process. For example, once an item is at the highest level of upgrading for any rank (Explorer, Adventurer, Veteran, Champion, Hero, or Mythic) it won't require Flightstones to be upgraded. This change is intended to allow players to get their gear up to the highest possible ilvl on all their characters instead of relying on seasonal loot.
It's also essential to use crests in a wise manner, as they are only used for one purpose. For instance, it's a good idea use all of your Whelpling-rank crests with the best equipment available, and then keep Drake and Wyrm crests for the next round of upgrades you're planning to make. This is particularly true for items such as rings and trinkets that occupy multiple slots. The discount on the account will only be applicable if all slots on the character are filled with high-quality equipment.