Cheapest priced copy (March of the Machine): $0.49 at Card Kingdom, near mint, their price list as of .
Progenitor Exarch 
Creature — Phyrexian Cat Cleric · 1/2 · Rare · March of the Machine · #32
When this creature enters, incubate 3 X times. (To incubate 3, create an Incubator token with three +1/+1 counters on it and "{2}: Transform this token." It transforms into a 0/0 Phyrexian artifact creature.)
{T}: Transform target Incubator token you control.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $0.49 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| March of the Machine | 32 | Rare | $0.49 | $0.79 |
| March of the Machine | 348 | Rare | $0.59 | $0.49 |
| March of the Machine Promos | 32p | Rare | $0.49 | $0.79 |
| March of the Machine Promos | 32s | Rare | — | $0.69 |