Hello! "un ojo de la cara" is used when something is really expensive. "he comprado un par de zapatos y me han costado un ojo de la cara" mañana voy a devolverlos. sounds better that " mañana voy a hacer una devolución" .

Hola! "un ojo de la cara" is a Spanish expression that means that something is or was very expensive. Another example would be this one: "Finalmente compraste la guitarra que querías?" ( Did you finally buy the guitar you wanted? ) "No, investigué en internet y cuesta un ojo de la cara." ( No, I researched on the internet and the price is really high. ) Espero que esta explicación te ayude!

in english would be ...cost arm and leg... or ...break the bank..