Sophisticated Architecture of Parkside Views with Access from Mombasa Road
You can usually expect a drop in prices when there is an over-supply of homes or land in a given area. You can't move the overage to another area to keep prices stable.
Scarcity causes prices to rise when there isn't enough land or if there aren't enough homes in a given area. Even if land is available on which to build more homes, the time it takes to construct them cannot meet immediate property needs, so demand will remain constant or rise.