Does an artificer's magical focus replace costly spell components?

Question

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?

Answer 1

You still have to use costly material components.

The current wording of the Artificer's spellcasting ability is:

You must have a spellcasting focus—specifically thieves’ tools or some kind of artisan’s tool—in hand when you cast any spell with this Spellcasting feature

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:

A character can use a component pouch or a spellcasting focus (found in chapter 5, “Equipment”) in place of the components specified for a spell. But if a cost is indicated for a component, a character must have that specific component before he or she can cast the spell.

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.