You can click on the pictures to see the original home ads in the Sears catalog, with prices (e.g. http://www.searsarchives.com/homes/images/1908-1914/1911_011...) $1062 for the parts to a beautiful American Craftsman style bungalow ($34,394.38 adjusted for inflation)! Some assembly required :)
On a tangential note: Sears killed the mail order catalog in 1993, just as the Internet was starting to take off. They could have been Amazon. Now, even their landmark highrise, the Sears Tower, has been unceremoniously renamed Willis Tower.
I still like the idea of mail order house parts & plans though. Someone should start a startup to make and build them.