医院可以为一袋生理盐水收取高达700美元的费用，而这对他们来说平均每袋只成本2.00美元。谁能向我解释一下，这怎么就不是一种合法化的欺诈形式呢？请让我明白过来。

Hospitals can charge up to $700 for a bag of saline, which only costs them an average of $2.00 per bag. Someone explain to me how this is NOT a form of legalized fraud? Please make it make sense.