We have sweaters at a very good price-only25.句中的at怎么理解

问题描述:

We have sweaters at a very good price-only25.句中的at怎么理解

在表示价格时可用at 和for.但两者有区别.at一般表示单价,for表示总价
This kind of ball-pens is sold at five dollars each.
这种圆珠笔每支售价5 元
for用来表示总价(通常指买卖一件或多件东西的“等价值”),如:
I paid 40 dollars for a cotton dress
He sold the house for 30,000 dollars.
应该够清楚了吧.