Never buy a pig in a poke .

不要隔着口袋买小猪。（喻未见真货，不要瞎买）

Never buy a pig in a poke.

千万别买袋子里的猪。

Sell a pig in a poke.

猪装在口袋里卖。

The new car you bought is a pig in a poke.

你买的那辆新车是瞎买的，没什么用。

I want to see the tennis racket before I agree to the price. I don't want to buy a pig in a poke.

我想先看看网球拍然后才能接受这个价位，我可不想胡乱买东西。