“buy a pig in a poke”别理解成“买袋子里的猪”，真实含义是看不清东西而瞎买；未见真货；不要瞎买。

【例句】
He always seems to buy a pig in a poke and never learns from his mistakes.
看来他总是看不清东西而瞎买，从不吸取教训。

Buying something online is like buying a pig in a poke.
网上购物就喜欢一顿乱买。