Prices won't lower at all. This is a movement by large SF landowners to raise the worth of the land they already own, using credulous tech kids as patsies. They will use new units as tax writeoffs and collateral for loans to scarf up land in gentrifying neighborhoods in other cities and other countries, so they'd rather let them sit vacant than let rents or prices drop by a penny.

This is the same as when pharmaceutical companies set up and fund patient advocacy organizations.