Cheapest priced copy (Unfinity): $0.35 at Card Kingdom, near mint, their price list as of .
Coming Attraction 
Sorcery · Common · Unfinity · #135
Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Open an Attraction. (Put the top card of your Attraction deck onto the battlefield.)
Legal inCommander
Banned inLegacyVintagePauper
Not legal inBrawlStandardPioneerModern