https://tappedout.net/mtg-decks/budget-beginner-teaching-decks-1-green/
https://tappedout.net/mtg-decks/budget-beginner-teaching-decks-2-red/
^^ the two decks I used, I played green and the ai was red. Still getting the hang of this game but with over like 50k cards in the library and endless combos it's so deep. The AI is quite smart on Forge too. I've never played MTG in my life so this is all new to me.
Yeah the game costs a lot if you're trying to do everything. For the best bang for your buck I'd look at trying Commander with one of the pre-built decks and buy singles to upgrade. Either that or get into Draft. Constructed formats are the real money pits.
Commander is great. That's a new format for me so I just started playing. I started with a precon and have been building from there. I pretty much exclusively play commander now lol