Hackers. Interesting stuff.
So, in a game recently, I drew hackers as a free card, in a late generation. I could spare the energy, and I wanted to fund a mildly risky banker. So, I played hackers, at a cost of 1. (Free card, and the discount made is only cost 1 to play).
But really the cost was 2, right? I could have sold the card for a dollar. That's true of any randomly drawn free card.
So, even if we ignore the -2 MC to my opponent, since we don't know that it will matter, we can say that my cost was 0, since I immediately have 2 more MC at the start of the next gen. (Assuming that I was not 1 or 2 MC short of playing some other important card.)
Anyway, in the game in question, I ended up winning banker easily, and I went into final greenery phase thinking it was going to be a tie, and I would win the tiebreak.
Oops, no. The two greeneries my opponent placed (I accounted for these) also added one point to herbivores.
I lost by one point.