Cheapest priced copy (March of the Machine Commander): $0.49 at Card Kingdom, near mint, their price list as of .
Schema Thief 
Creature — Vedalken Rogue Artificer · 3/3 · Rare · March of the Machine Commander · #111
Flying
Whenever this creature deals combat damage to a player, create a token that's a copy of target artifact that player controls.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| March of the Machine Commander | 24 | Rare | $0.49 | — |
| March of the Machine Commander | 111 | Rare | $0.49 | — |
5 rulings from Wizards of the Coast
- 14 April 2023If the copied artifact is copying something else, then the token enters the battlefield as whatever that artifact copied.
- 14 April 2023If the copied artifact is a token, the token that’s created copies the original characteristics of that token as stated by the effect that created that token.
- 14 April 2023Any enters-the-battlefield abilities of the copied artifact will trigger when the token enters the battlefield. Any “as [this artifact] enters the battlefield” or “[this artifact] enters the battlefield with” abilities of the copied artifact will also work.
- 14 April 2023Each of the tokens copy exactly what was printed on the original artifact and nothing else (unless that artifact is copying something else or is a token; see below). It doesn’t copy whether that artifact is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, or any non-copy effects that have changed its power, toughness, types, color, and so on.
- 14 April 2023If the copied artifact has {X} in its mana cost, X is 0.