How much does air cost?

How much does air cost?
Air is basically "free" to anyone around the world. We breathe it all day, every day, and we do so to stay alive. That said, we might look just a bit further.

There might be instances where air does cost money. It costs money to compress air, so compressed air might come with a fee attached. We sometimes have to pay to air up vehicle tires or a SCUBA tank. Certainly the individual gases in air cost something if we wish to get them separately. This is true when we want oxygen, nitrogen or any of the other gases found in air in a pure form. In liquid (cryogenic) form, the cost of the individual gases rises higher, just as you might expect.