It's a matter of limited supply and increased demand.

这是一个供小于需的关系。

youdao

Survival for twins, who must compete for a limited supply of milk, is hard.

双胞胎必须互相争夺有限的母乳以生存，所以他们都能活下来很不容易。

youdao

There is, presumably, a limited supply of reputation and attention in the world at any point in time.

大概在世上的任何时间任何地点，声誉和注意力的供给都是有限的。

youdao

They form in areas with strong winds but a limited supply of sand.

VOA: special.2010.01.04

Food and water were in limited supply.

VOA: special.2009.08.10

Malthus argued that populations are always limited by the food supply.

VOA: special.2009.02.25

Fierce competition and a limited supply of talent is resulting in high turnover rates.

ECONOMIST: Human resources

Plastic bags are banned to prevent litter, and modern hotel rooms are in limited supply.

FORBES: Meet the Relatives

But given a limited supply the price of gas is just the price of gas.

FORBES: Links 4 Nov: The Price Of Gas Is Just The Price Of Gas, Anti-Gouging Laws Be D'mned