Cheapest priced copy (Coldsnap): $0.35 at Card Kingdom, near mint, their price list as of .
Balduvian Frostwaker 
Creature — Human Wizard · 1/1 · Uncommon · Coldsnap · #28
{U}, {T}: Target snow land becomes a 2/2 blue Elemental creature with flying. It's still a land.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Coldsnap | 28 | Uncommon | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 15 July 2006Balduvian Frostwaker’s effect has no duration. The snow land is a creature as long as it’s on the battlefield.
- 15 July 2006If an affected land later loses the supertype snow, Balduvian Frostwaker’s effect doesn’t end. The land will remain a creature.
- 1 August 2008A noncreature permanent that turns into a creature can attack, and its {T} abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn’t matter how long the permanent has been a creature.