The value of the last breath of air

A comment about price vs. cost vs. value triggered a lingering thought experiment:

Suppose the intergalactic bypass got built and Earth was destroyed to make room, and you were one of the few survivors of the demolition. Let's further suppose that you were one of two trillionaires (infinitaires even) bidding in an auction for a can containing the last breath of air, that only one of you can breathe. After that, you die; the only question here is whether to postpone your demise by half a minute. There are no heirs (they either are dead or soon will be too), no charitable causes (the poor are dead, so are charismatic megafauna), and no liabilities (the revenue service is no more, and the phone company is out of business).

What is that can of air (as likely to be "fresh" as it is to be a sample taken from a sewer) worth? You might want to say it has infinite value, but I'm not so sure. Life seems of infinite value only if you don't know how much of it you have. Somehow I can't see myself spending my entire personal worth for one last breath of air. OTOH, a cool trillion is pointless if you can't spend it.

So much for the last breath of air. What about the one you're taking this very moment? What is it worth?