Cheapest priced copy (Onslaught): $6.99 at Card Kingdom, near mint, their price list as of .
Aurification 
Enchantment · Rare · Onslaught · #6
Whenever a creature deals damage to you, put a gold counter on it.
Each creature with a gold counter on it is a Wall in addition to its other creature types and has defender. (Those creatures can't attack.)
When this enchantment leaves the battlefield, remove all gold counters from all creatures.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $6.99 to $22.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Onslaught | 6 | Rare | $6.99 | $22.99 |
One ruling from Wizards of the Coast
- 1 October 2008Aurification gives the creature type “Wall” to creatures with gold counters on them in addition to granting them defender.