price表示“价格”、“价钱”的意思时，是可数名词，复数形式是 prices，例如：

Prices are going up. 物价正上涨。（《薄冰英语惯用法词典》 price 词条）

询问价格时我们可以说：

What's the price of the...？

What price is the...？

How much is the+ 单数名词 + ？

How much are the + 复数名词 + ？

例如：

What's / What is the price of the car？

= What price is the car？

= How much is the car？

这辆汽车的价格是多少？

How much are the apples？这些苹果多少钱？

【注意】the price of the 后面可以接单数名词或者复数名词，例如：

The price of the vegetables is going up. 蔬菜涨价了。

The prices of the watches are very low at that store.

=Watches are very cheap at that store. 那家店的手表很便宜。（《外研社英汉多功能词典》price词条）

所以，What are the prices of the shoes? / What's the price of the shoes? / What are the prices of the apples / desks? 也是正确的。

但是，不能说：How much is the price of...?