SE,
I hope that you reconsider future "gil sink" plans like the housing one and think about using other methods to rewards FC's. Instead of using content as a means of solving economic issues, please consider using FC points instead, they're untradeable and they are relatively hard to earn.
I don't know what recent data you have managed to gather but I would assume that the whole FC house deal has caused the following events:
1. More FC's resorting to selling content (do you really want this?)
2. More incentive for RMT to make gil (and probably sell it to people that are buying primal runs etc.)
It's not too big of an issue anymore now since the prices have dropped drastically, but I think the original plan failed and I hope SE learns from this.