Cheapest priced copy (Double Masters): $0.35 at Card Kingdom, near mint, their price list as of .
Riddlesmith 
Creature — Human Artificer · 2/1 · Uncommon · Duel Decks: Elves vs. Inventors · #39
Whenever you cast an artifact spell, you may draw a card. If you do, discard a card.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
4 printings · $0.35 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 65 | Uncommon | $0.35 | $0.49 |
| Duel Decks: Elves vs. Inventors | 39 | Uncommon | $0.39 | — |
| Neon Dynasty Commander | 96 | Uncommon | $0.35 | — |
| Scars of Mirrodin | 40 | Uncommon | $0.35 | $3.49 |
2 rulings from Wizards of the Coast
- 7 August 2020You draw a card and discard a card all while Riddlesmith's ability is resolving. Nothing can happen between the two, and no player may choose to take actions.
- 7 August 2020An ability that triggers when a player casts a spell resolves before the spell that caused it to trigger. It resolves even if that spell is countered.