Cheapest priced copy (Alliances): $0.35 at Card Kingdom, near mint, their price list as of .
Astrolabe 
Artifact · Common · Alliances · #118b
{1}, {T}, Sacrifice this artifact: Add two mana of any one color. Draw a card at the beginning of the next turn's upkeep.
Legal inCommanderLegacyVintagePauper
Not legal inBrawlStandardPioneerModern