Cheapest priced copy (Phyrexia: All Will Be One): $0.79 at Card Kingdom, near mint, their price list as of .
Encroaching Mycosynth 
Artifact · Rare · Phyrexia: All Will Be One Promos · #47p
Nonland permanents you control are artifacts in addition to their other types. The same is true for permanent spells you control and nonland permanent cards you own that aren't on the battlefield.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $0.79 to $3.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Phyrexia: All Will Be One | 47 | Rare | $0.99 | $1.49 |
| Phyrexia: All Will Be One | 380 | Rare | $0.79 | $2.99 |
| Phyrexia: All Will Be One Promos | 47p | Rare | $3.99 | $2.99 |
| Phyrexia: All Will Be One Promos | 47s | Rare | — | $2.79 |
2 rulings from Wizards of the Coast
- 4 February 2023Encroaching Mycosynth turns all permanents you control into artifacts. Permanent spells you control become artifact spells in addition to their other types, and nonland permanent cards you own in other zones become artifact cards in addition to their other types.
- 4 February 2023Encroaching Mycosynth's ability causes Auras to become artifacts. This makes it more likely that another effect (such as that of March of the Machines) will make those artifact Auras into creatures. An Aura that's also a creature can't enchant anything. It's unattached the next time state-based actions are checked, and then immediately put into its owner's graveyard as a second state-based action.