Can Defy still counter Bullet Time after the opponent recycles 2 for it?

Defy uses Bullet Time's printed cost, so it still costs only 1 energy for Defy purposes. However, the choice of how much power to pay for Bullet Time happens on resolution, not as an additional cost to play it. If the opponent recycles 2 before giving you a reaction window, you cannot Defy afterward. You must Defy before they decide how much power to pay.