>> Materials can be used to purchase any skin/celebration/quip etc. Materials can be bought with gold.

This is what we thought too but theres no way to buy materials with gold. Only through Apex packs. Eg [0], [1].

[0] https://www.shacknews.com/article/109806/how-to-get-crafting...

[1] https://www.techjunkie.com/get-crafting-metals-apex-legends/