"买的没有卖的精" simplify means "买方没有卖方精明"。买的 = 买东西的（人）= buyers; 卖的= 买东西的（人）= sellers. As we all know that most businessmen are very shrewd and tough, so it's hard for us to deceive them. So this idiom tells us that "never think about taking advantage of those businessmen, they always outsmart us". Normally we use this idiom when we have to admit that those who're selling things are smarter than us. For example, If you spent hours haggling with someone who's selling things and finally you got those things for half of the tag price. I think you must be very happy, but when you got home and your husband told you that he could buy these things everywhere at the lower price. You would say this to yourself "哎，买的没有卖的精＂

买的没有卖的精，它的意思是去买东西的人总是被会被卖东西的人占便宜。设想一下，比如你是一个商店里某货物的推销员，再卖货之前你肯定会接受各种培训，比如关于货物本身的它的对应人群和消费者的购物心理等等。对于购物者一方来讲他们是无准备的，对于推销者一方他们是有准备的。 相似的谚语还有：关公面前耍大刀。

完整的说法是“从南京到北京，买的不如卖的精”。from nanjing to beijing, sellers are aways smarter than buyers.

比如 商场促销，打折，很多人会去买，并且觉得占了便宜。这是个对于这些买家就可以说，买的没有卖的精。因为羊毛还是出在羊身上，归根到底，出钱的还是买家，卖家只是用个了营销手段。

If you don't want to get ripped off here in China, you need to learn some haggling skills. Especially when you buy clothes in some markets or even some shopping malls, I would feel it's reasonable or acceptable if I pay the half the asking price or even lower. Even so it's a little bit early for you to be happy and start to calculate how much you save. You never know, you might be able to pay less for the same thing just around the corner. 总之，我们买的没有卖的精！