Cheapest priced copy (Duel Decks: Elspeth vs. Tezzeret): $0.35 at Card Kingdom, near mint, their price list as of .
Blinding Beam 
Instant · Common · Mirrodin · #7
Choose one —
• Tap two target creatures.
• Creatures don't untap during target player's next untap step.
Entwine {1} (Choose both if you pay the entwine cost.)
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duel Decks: Elspeth vs. Tezzeret | 28 | Common | $0.35 | — |
| Modern Masters | 7 | Common | $0.35 | $0.49 |
| Mirrodin | 7 | Common | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 7 June 2013The second mode affects all creatures during the player’s next untap step, including creatures controlled by other players (who may have untapped because of Seedborn Muse, for example) and creatures that weren’t on the battlefield when Blinding Beam resolved.