Magic: The Gathering | Avatar: The Last Airbender Commander’s Bundle | Includes 1 Collector Booster, 9 Play Boosters, 5 Borderless Cards, 30 Lands + Exclusive Accessories

I don't know how good this is so take it with a grain of salt, but they did make a commander bundle: https://www.amazon.com/dp/B0FHJJS17L You'd still need to make the deck yourself, but that would probably be a good starting point? Alternatively, you could look for budget TLA EDH decks on something like Moxfield, that has an option to buy the deck directly from a vendor (I personally prefer CardKingdom but they tend to be pricier than the other options). When you add it to your cart, you can skim through and see if there are any crazy expensive cards that you could just not order. Not sure how much those decks go for - some EDH decks can be built on a very low budget, but Universes Beyond can vary pretty wildly pricewise.