Los Jardines de Micosintético

If the copied artifact has {X} in its mana cost, X is 0.

If the copied artifact is copying something else, then The Mycosynth Gardens becomes a copy of whatever that artifact copied.

The Mycosynth Gardens copies exactly what was printed on the original artifact and nothing else (unless that permanent is copying something else; see below). It doesn't copy whether that artifact is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, and so on.