To my knowledge, an artificer must use thieves' tools, artisan's tools they are proficient with, or an infusion as a magical focus when casting spells.
However, some artificer spells, such as Identify and Revivify, have material components that normally wouldn't be handled via a spellcasting focus or component pouch and must be purchased.
Since artificers are unable to use traditional spellcasting material components, do they need to purchase costly material components for spells like Identify and Revivify, or does their focus replicate these material components too?
Best Answer
You still have to use costly material components.
The current wording of the Artificer's spellcasting ability is:
This wording means that you can use your tools (or infusion as detailed later on) as a spellcasting focus and that you must use an appropriate spellcasting focus. Because it is still a spellcasting focus, the rules for a spellcasting focus remain as follows:
Since the costly component rules are part of the spellcasting focus rules, and whatever an artificer chooses to use to cast spells is still considered a spellcasting focus, the costly material requirement still applies.