How to get the Artificer class?

I really want to play an Artificer character, but I don't know how to get it. Some people say that you can get it by buying a subclass. "Eberron: Forge of the Artificer" book, because it comes with a bunch of Artificer subclasses. Other people say that you need to get "Tasha's Cauldron of Everything" and then buy the subclasses that you want afterwards. I'm kinda tight on money and I want to spend as little as possible on this, but I am willing to spend as much as I need to. Eberron is $19.99 whereas Tasha's is $29.99. Is it possible to buy the class as a standalone for cheaper? Idk I'm just kinda lost.