Ok, here's my reasoning: if you make it three turns, then it could cost 12
and STILL be broken. If you make it only last one turn, then it kind of sucks as a stall, because even if you chain them, you're spending all/most of your quanta production (early to mid-game, when quanta production matters most) on locking down theirs (or really, only half of theirs because they have a 50/50 pillar/pendulum split). So it still sucks. By locking down their quanta for two turns, you more-or less gain a one-turn advantage on quanta production. Please discuss.