at a price 等于什么

at a price 等于什么 at a good price rationalization at a price be assessed at a price 价格合理是at a good price还是at good price 请问at a price of & at the price of 是at a low price 还是in a low price at a cheaper price 和in a cheaper price at a good price 还是 for a good price in half a price还是 at half a price? at a good price 为什么price不加s?不是表示价格就要加s吗?到底在什么 price的具体用法以高价,低价什么说?我见过at a high price 和in low price.那么有没有in