Rather than writing everything out, using multipliers, and doing all of the stuff we do for the article, you can simply add up the total value of all the mythics in the set (in this case, roughly $115), divide by the total number of mythics in the set (generally 15 but sometimes slightly different Throne of Eldraine has 15, which would give us $115.05 / 15 = $7.67) to get the average value of a mythic rare, and then finally multiply by the number of mythics you'll get from an average box (here's a cheat sheet: the average box as 4.5 mythics, 31.5 rares, 108 uncommons, and 360 commons)
Depending on the number of permanents 2 CMC or lower, you could be looking at 10+ extra mana for the turn that you cast it
In English, Crown Zenith is full of valuable cards, while its Japanese counterpart, VSTAR Universe, features high prices and includes cards that aren't as expensive in English
A Special Illustration Rare in every 76 packs