The idea of the Mystery Booster is that you dont know what cards you are going to get until you open it up the mystery is a feature of the product
Most non-Iconic, non-Enchanted Attack of the Vine singles stabilize within 7-10 days of the July 24 launch
Exchanging those with him is an easy way to get more mounts, minions, bardings, orchestrion rolls, framer's kits, and even a few items that can be used in glamours
See more Add To Wishlist Restock Notice Gatherer & Rulings (opens in new tab) NM EX VG G 4 available @ $32.99 Add to Cart 1 2 3 4 $28.04 Out of stock
It could be a bonus card randomly inserted into certain Secret Lairs (a la the Smothering Tithe from Spongebob drops), or maybe it's an add-on for spending a certain amount on the Secret Lair website, which shouldn't be that hard to do with these drops
While its definitely helpful to have access to the rarer cards in a deck, its also fully possible to play a competitive deck without Legendary cards and just a few Rare and Super Rare