Cheapest priced copy (Tenth Edition): $0.35 at Card Kingdom, near mint, their price list as of .
Crafty Pathmage 
Creature — Human Wizard · 1/1 · Common · Onslaught · #77
{T}: Target creature with power 2 or less can't be blocked this turn.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
4 printings · $0.35 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Tenth Edition | 77 | Common | $0.35 | $0.49 |
| Ninth Edition | 71 | Common | $0.35 | — |
| Ninth Edition | 71★ | Common | — | $0.49 |
| Onslaught | 77 | Common | $0.35 | $0.99 |
One ruling from Wizards of the Coast
- 4 October 2004If you increase the power of the targeted creature after the ability resolves, it still can't be blocked that turn.