The problem of rising values in homes and their being bought up so they can be torn down is not confined to urban areas. Farmland is disappearing in so many places it will be a wonder if there is any left by 2050. It is so difficult to make a living consistently at farming that developers don't have a lot of trouble most of the time buying up farms to build housing developments. This, of course, not only ruins the landscape but results in problems with drainage and runoff, more roads having to be built, along with more schools, etc. We have a program here in Maryland whereby a farm owner can place his property in a sort of trust which allows him to continue to occupy and farm it for his lifetime, but it can't thereafter be sold; it remains green space. He gets tax breaks and other incentives to allow him to get by financially even in case of drought, crop failure, and the other normal perils of farming. Unfortunately, rarely taken advantage of.