Cheapest priced copy (Throne of Eldraine): $0.49 at Card Kingdom, near mint, their price list as of .
Worthy Knight 
Creature — Human Knight · 2/2 · Rare · March of the Machine Commander · #217
Whenever you cast a Knight spell, create a 1/1 white Human creature token.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
5 printings · $0.49 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Throne of Eldraine | 36 | Rare | $0.49 | $0.79 |
| Throne of Eldraine | 341 | Rare | $1.99 | $3.49 |
| March of the Machine Commander | 217 | Rare | $0.49 | — |
| Throne of Eldraine Promos | 36p | Rare | $0.49 | $2.99 |
| Throne of Eldraine Promos | 36s | Rare | — | $0.69 |
3 rulings from Wizards of the Coast
- 4 October 2019If an effect refers to a “[subtype] spell,” it refers only to a spell that has that subtype. For example, Knights' Charge is a card with “Knight” in its name and benefits Knights, but it isn't a Knight card.
- 4 October 2019Worthy Knight's triggered ability won't trigger when you cast it because it's not on the battlefield yet.
- 4 October 2019Worthy Knight's ability resolves before the spell that caused it to trigger. It resolves even if that spell is countered.