Cheapest priced copy (Mirrodin Besieged): $7.49 at Card Kingdom, near mint, their price list as of .
Myr Turbine 
Artifact · Rare · Mirrodin Besieged · #117
{T}: Create a 1/1 colorless Myr artifact creature token.
{T}, Tap five untapped Myr you control: Search your library for a Myr creature card, put it onto the battlefield, then shuffle.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $7.49 to $11.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Mirrodin Besieged | 117 | Rare | $7.49 | $11.99 |
One ruling from Wizards of the Coast
- 1 June 2011You can tap a Myr that hasn’t been under your control since your most recent turn began to pay for the cost of the second activated ability.