Waluta jako materiał rzemieślniczy, nie portfel
The unusual part of this game is that the trading unit and the crafting material are the same object. An orb spent on a trade is an orb not spent on an item, and every purchase competes with a craft. That is why orders in Path of Exile 2 currency are sized in orbs against a plan rather than as a round number.
It also explains why finished gear is often cheaper than making it. A craft has no guaranteed outcome, while a listed item has a known one, and the difference between them is the price of the failed attempts. Comparing an Path of Exile 2 items listing against the orbs a craft would cost is the calculation worth doing before you spend.
The rule most players settle on is to buy the pieces that gate progress and craft the ones where a partial result is still useful. The escrow behind either route is described in the Eloboost24 buying guide.