in, at
in the shop 没有问题,是在商店、小店里
但价格前用何种介词还是很困扰人的,我的总结:
buy for 后面跟钱的数额,表示以…价格买下,如:He bought it for ten dollars. 他以10美元买下它。
但这里用at的原因是,at a price/ at a speed /at a pace 以某种价格/速度/作方式状语的话,要用at,习惯用法
I buy a pair of shoes in that shop at a good price. 初一上教材第七单元中有这个用法,
以一个什么样的价格,要用介词on
...in that shop with a good price.
in that shop at a good price
I buy a pair of shoes in that shop at a good price