pig in a poke

Etymology
Reportedly from the practice of substituting a butchered cat, etc. for a suckling pig when sold in a sack at a market. Other theories circulate but all involve the purchase of a cat in a bag, where the buyer expected better.

Noun

 * 1)  Something whose true value is concealed or unknown and may be lower than expected by the buyer or claimed by the seller, especially something offered for sale.

Translations

 * Albanian: derr në thes
 * Arabic: سَمَك فِي مَاء
 * Chinese:
 * Mandarin: 瞎買東西,
 * Czech: zajíc v pytli
 * Dutch:
 * Estonian: siga kotis
 * Finnish: sika säkissä
 * French:
 * German:
 * Greek: γουρούνι στο σακί
 * Hebrew:
 * Hungarian:
 * Icelandic:
 * Indonesian: kucing dalam karung
 * Japanese: (impulsive buying)
 * Latvian: kaķis maisā, cūka maisā
 * Norwegian:
 * Polish: kot w worku
 * Portuguese: nabos em saco
 * Russian:
 * Spanish: dar gato por liebre
 * Swedish: