Cheapest priced copy (Adventures in the Forgotten Realms): $0.35 at Card Kingdom, near mint, their price list as of .
Plate Armor 
Artifact — Equipment · Uncommon · Adventures in the Forgotten Realms · #32
Equipped creature gets +3/+3 and has ward {1}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
Equip {3}. This ability costs {1} less to activate for each other Equipment you control. ({3}: Attach to target creature you control. Equip only as a sorcery.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
3 printings · $0.35 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Adventures in the Forgotten Realms | 32 | Uncommon | $0.35 | $0.99 |
| Foundations Jumpstart | 100 | Uncommon | $0.35 | — |
| The List | AFR-32 | Uncommon | $0.35 | — |
2 rulings from Wizards of the Coast
- 23 July 2021If a player casts a spell that targets multiple permanents their opponent controls with ward, each of those ward abilities will trigger. If that player doesn't pay for all of them, the spell will be countered.
- 23 July 2021If a creature with ward is equipped with Plate Armor, becoming the target of a spell or ability an opponent controls will cause both ward abilities to trigger.