Sell sb short

hard sell 強迫推銷
I wanted a cheap car without a lot of extras. But the salesman gave me a hard sell so I ended up with stuff I didn't need, like leather seats, a sun roof and a lot of other things.
我本來只想買一輛沒什麼額外設備的廉價車，可那個推銷員硬是讓我買下了皮座椅、天窗之類那些並不必需的設備。
sell a bill of goods 以花言巧語騙取信任
My opponent is selling you a bill of goods when he promises to spend more on schools and cut taxes too. You ask him how he can spend more money without raising taxes!
我的對手既保證要給學校多經費，又答應減稅，其實這兩者不可兼得。他怎麼可能做到既多花錢又不加稅呢?
A bill of goods意思是進貨單。注意，這只是開列貨品的單子，不是實物。如果有人要你出錢買的只是貨單，他很可能在行騙。
sell somebody short 小看某人
Don't sell that man short. He's one of the smartest lawyers in town. You'd be wise to hire him if you're in trouble - he seldom loses a case.
可別小看了這個人。他是城裏最能幹的律師之一。你要有麻煩找他才對，他從沒輸過一場官司。
意思很像中文"把人瞧扁了"，也就是沒看到某人的長處。所以sell someone short意思就是"小看某人。"