Cheapest priced copy (Commander 2018): $0.49 at Card Kingdom, near mint, their price list as of .
Genesis Storm 
Sorcery · Rare · Commander 2018 · #30
When you cast this spell, copy it for each time you've cast your commander from the command zone this game.
Reveal cards from the top of your library until you reveal a nonland permanent card. You may put that card onto the battlefield. Then put all cards revealed this way that weren't put onto the battlefield on the bottom of your library in a random order.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2018 | 30 | Rare | $0.49 | — |
8 rulings from Wizards of the Coast
- 13 July 2018If you choose not to put the nonland permanent card you reveal onto the battlefield, you’ll put it on the bottom of your library with the other cards.
- 13 July 2018Each Storm’s triggered ability can copy the Storm spell even if that spell is countered before that ability resolves.
- 13 July 2018If your commander was countered, that time you cast it still counts.
- 13 July 2018Each copy resolves one at a time. Any abilities that trigger on the permanent entering the battlefield resolve before the next copy resolves. The original spell is the last to resolve.
- 13 July 2018If your library no longer has any nonland permanent cards, you’ll reveal your library and then put it back in a random order.
- 13 July 2018The copies are created on the stack, so they’re not “cast.” Abilities that trigger when a player casts a spell (such as the Storm’s ability itself) won’t trigger.
- 13 July 2018Each Storm’s triggered ability counts only how many times you’ve cast your commander from the command zone before that triggered ability resolves. If you cast your commander again later, you won’t get another copy.
- 5 October 2018If you have multiple commanders, you’ll copy this spell for each time you’ve cast either of them. For example, if you’ve cast one commander once and one twice, you’ll copy this spell three times.