Cheapest priced copy (Dissension): $0.99 at Card Kingdom, near mint, their price list as of .
Elemental Resonance 
Enchantment — Aura · Rare · Dissension · #83
Enchant permanent
At the beginning of your first main phase, add mana equal to enchanted permanent's mana cost. (Mana cost includes color. If a mana symbol has multiple colors, choose one.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $0.99 to $8.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dissension | 83 | Rare | $0.99 | $8.99 |
4 rulings from Wizards of the Coast
- 1 May 2006This ability isn't a mana ability. It uses the stack.
- 1 May 2006Only the first main phase in a turn is the "precombat main phase," even if additional main phases are generated by some effect.
- 1 May 2006If the enchanted permanent's mana cost is {2}{W}{U}, this Aura's controller adds {C}{C}{W}{U}. If its mana cost is {X}{G}, this Aura's controller adds {G}. If its mana cost is {W/U}{W/U}, this Aura's controller chooses whether to add {W}{W}, {W}{U}, or {U}{U}. The choice may be different each time the ability resolves.
- 1 October 2009You get the mana whether you want it or not. If you don't spend it, it will disappear at the end of the current step (or phase).