TO BUY AND TO SELL SOMEBODY A PIG IN A POKE

WHEN YOU ARE BUYING WITHOUT LOOKING PRICES, IF YOU DON'T KNOW WHAT ARE YOU REALLY BUYING YOU ARE BUYING A PIG IN A POKE. IN SPANISH WE CAN SAY: "COMPRAR A CIEGAS". SO BE CAREFUL AND DON'T BUY A PIG IN A POKE.

BUT THERE IS A VERY SIMILAR IDIOM: TO SELL SOMEBODY A PIG ON A POKE AND IN SPANIH WE HAVE ANOTHER ONE: DAR GATO POR LIBRE, BEACOUSE YOU THING YOU ARE BUYING A THING BUT THEY ARE SELLING YOU ANOTHER THING.

SO: TO BUY A PIG IN A POKE MEANS COMPRAR A CIEGAS.

BUT: TO SELL SOMEBODY A PIG IN A POKE MEANS: DAR GATO POR LIEBRE.