Cheapest priced copy (Magic 2010): $0.35 at Card Kingdom, near mint, their price list as of .
Armored Ascension 
Enchantment — Aura · Uncommon · Magic 2011 · #5
Enchant creature
Enchanted creature gets +1/+1 for each Plains you control and has flying.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
4 printings · $0.35 to $3.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Magic 2010 | 3 | Uncommon | $0.35 | $2.99 |
| Magic 2011 | 5 | Uncommon | $0.39 | $1.49 |
| The List | SHM-2 | Uncommon | $0.35 | — |
| Shadowmoor | 2 | Uncommon | $0.39 | $3.99 |
3 rulings from Wizards of the Coast
- 1 October 2009This ability counts the number of Plains controlled by Armored Ascension’s controller, not the enchanted creature’s controller (in case they’re different players).
- 1 October 2009This bonus is not fixed; it changes as the number of Plains you control changes.
- 15 August 2010The ability cares about lands with the land type Plains, not necessarily lands named Plains.