Cheapest priced copy (Ice Age): $0.59 at Card Kingdom, near mint, their price list as of .
Dwarven Armory 
Enchantment · Rare · Ice Age · #182
{2}, Sacrifice a land: Put a +2/+2 counter on target creature. Activate only during any upkeep step.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.59 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ice Age | 182 | Rare | $0.59 | — |
One ruling from Wizards of the Coast
- 4 October 2004The ability can be activated during your opponent’s upkeep as well as your own. The upkeep restriction is there to avoid its use during combat.