Cheapest priced copy (Commander Legends): $0.35 at Card Kingdom, near mint, their price list as of .
Ring of Thune 
Artifact — Equipment · Uncommon · Magic 2013 · #213
Equipped creature has vigilance. (Attacking doesn't cause it to tap.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's white.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.35 to $1.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander Legends | 468 | Uncommon | $0.35 | — |
| Game Night: Free-for-All | 119 | Uncommon | $0.35 | — |
| Magic 2013 | 213 | Uncommon | $0.49 | $1.99 |