‘Sold Out’ even before building is built

The block of flats has not yet been built, and already a sign has gone up saying 'Sold Out'. What kind of building is this? That's what a reader pointed out to us. Well, who knows? 

There are suggestions that as soon as a building goes up, people involved in the property business start buying en bloc, in the hope of making a quick profit once the flats are ready and there is a demand for them. That may be good business for those in the property world, but for the average person who may wish to purchase a flat it means paying more than would have been the case if such property speculation did not take place or was not allowed.Anyway, that is what the suggestions say. Buy before time at 'ordinary' price and once the demand grows pay at an 'inflated price' to make a quick profit.

Is that the Gibraltar wants?