Cheapest priced copy (Masters 25): $0.35 at Card Kingdom, near mint, their price list as of .
Echoing Courage 
Instant · Common · Darksteel · #74
Target creature and all other creatures with the same name as that creature get +2/+2 until end of turn.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
5 printings · $0.35 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Masters 25 | 166 | Common | $0.35 | $0.49 |
| Conspiracy | 161 | Common | $0.35 | $0.79 |
| Darksteel | 74 | Common | $0.35 | $0.99 |
| Modern Masters | 143 | Common | $0.35 | $0.49 |
| The List | CNS-161 | Common | $0.35 | — |
4 rulings from Wizards of the Coast
- 16 March 2018If the target creature is an illegal target by the time Echoing Courage tries to resolve, the spell doesn't resolve. No creatures get +2/+2.
- 16 March 2018A face-down creature has no name, so it can't share a name with anything. This includes other creatures with no name.
- 16 March 2018Echoing Courage has only one target. Other creatures with that name are not targeted. For example, a creature with protection from green will still get +2/+2 if it has the same name as the target creature.
- 10 June 2022Unless a token is a copy of another permanent or was explicitly given a name by the effect that created it, its name is the subtypes it was given when it was created plus the word "Token." For example, if an effect creates a 1/1 Soldier creature token, that token is named "Soldier Token."