Get Enough of It

It is manmade, and thus finite, and yet it grows on trees
(or ten percent does, and the rest in cotton fields).
It can be traded for almost anything, for profit.
Civilized people cannot get enough of it.

It is universal, and immutable, and infinite,
Yet you cannot get more once you've been rid of it.
It is only traded for one thing, and always at a loss;
Civilized people consider only keeping it a cost.

I disagree strongly that money is time;
To think they are opposites I'm more inclined.