Protect what you still need
Quest items, off-role gear and materials for a planned profession step should stay out of the quick-sale pile. Read the tooltip and quest log. Keep uncertain items separately until you know their purpose; a small holding pile beats destroying something you need next.
Check its use on your character
Quality colour alone does not make an upgrade. Check armour type, weapon compatibility, stats and requirements. Gear for your second role may be worth more to you than a small immediate payment. Give each saved item a purpose instead of banking every hypothetical future need.
The vendor offers a straightforward baseline
The vendor value is a concrete offer for your item. Auction House listings are asking prices. Compare identical items and subtract actual selling costs. A tiny premium may not justify repeatedly relisting it.
Disenchanting is irreversible
Learn Enchanting and check whether the specific item can be disenchanted. Quality colour alone is not enough. Disenchanting destroys it and the materials can vary. Without a reliable yield table, there is no guaranteed disenchanting value to quote.
Three common decisions
Keep a material needed for your next craft. Compare spare tradable armour with identical listings. For a disenchantable item, also consider the possible materials. Missing price or yield information leaves the comparison unresolved; it does not automatically beat the vendor.
Sort the same bag using three concrete decisions
Suppose you have Linen Cloth, a green piece of armour and an unfamiliar quest item. Split the cloth according to your plan: if you are about to make bags or bandages, keep the quantity required. The remainder is a possible sale, not an automatic instruction to sell. A full bag is first an organisation problem, not proof that everything inside is worthless.
Read the armour’s requirements and attributes first. If you can use it now, or it supports a second role you actually play, set it aside. Otherwise check its binding and vendor offer. If tradable, compare identical items at the Auction House. If considering disenchanting, check the actual ability and accept that the item will be destroyed; an unknown result is not a guaranteed source of profit.
Keep the unclear quest item until you know which task it belongs to. Look through your quest log and check whether the next step still needs it. Reserve a small fixed space for these unresolved cases. They will not take over your whole bank, and you avoid hurriedly selling something you would immediately need to find again.
Build a short sorting routine
On a town visit, separate personal supplies, bound gear and tradable goods. Sell obvious clutter, examine the interesting remainder and limit how much uncertain stock you keep. Price imports help, but their date and market must match your situation.