That 1993 Costa Rican 50 Céntimos Bill? It's a Fake

Short answer: It's counterfeit. The Banco Central de Costa Rica never issued a 50 céntimos note in 1993 (or any year). The 50 céntimos denomination existed only as a coin.

The note you're describing is likely a fantasy reproduction or a misidentified 5,000 colones bill (which was issued in the 1990s series). Genuine 1990s-series notes feature distinct security threads, watermarks, and intaglio printing—none of which appear on the 50 céntimos "note."

Collector value: Zero as legal tender. As a novelty item, perhaps a few dollars to a curiosity collector—but it has no numismatic standing.