一、be sold at  指商品“以...价格比率”售出，后接price 或“带有比价的具体数额”。例如：

1. There carpet is sold at $ 25 off the marked price.  这些地毯以低于标价25美元售出。

来自辞典例句

2. The wine glasses were sold at half price because of blemishes in the crystal. 酒杯因晶质玻璃有瑕疵以半价出售。

来自辞典例句

二、be sold for  指商品“以...的价格”售出，for表示“交换关系”（即：卖掉某物获得多少钱），后接具体数额。例如：

1. Rumour has it that tickets were being sold for £300.  据谣传，票卖到了300英镑。

来自柯林斯例句

2. The painting was sold for £665,000 — a record for the artist.  这幅画卖了665,000英镑，是这个艺术家最贵的一幅了。

来自柯林斯例句