You don't need to buy expensive booster boxes to start
ET: Weve received a statement from The Pokmon Company International regarding this situation, which is reproduced in full below
Panharmonicon isn't a super widely played card despite the popularity of ETB cards, so I don't expect to see Elesh Norn outside of dedicated ETB decks or in tables that aren't expecting powerful cards like this one
If the opponent tries to Special Summon from their Extra Deck while Lost Wind is in the GY, they can also set Lost Wind for free
I think its maybe a better pick for the 99 than as your commander, but its not a terrible choice if you just want to ensure your lifegain deck has some extra draw
For tokens you'll actually play with, the standard card format is the right choice it sleeves up correctly, shuffles like a real card, and sits flat on the battlefield