Cheapest priced copy (Marvel's Spider-Man): $1.99 at Card Kingdom, near mint, their price list as of .
Strength of Will 
Instant · Rare · Marvel's Spider-Man · #267
Until end of turn, target creature you control gains indestructible and "Whenever this creature is dealt damage, put that many +1/+1 counters on it."
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
3 printings · $1.99 to $5.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Marvel's Spider-Man Promos | 118s | Rare | — | $5.99 |
| Marvel's Spider-Man | 118 | Rare | $1.99 | $1.99 |
| Marvel's Spider-Man | 267 | Rare | $2.49 | $2.99 |