Some people do not realize they could get bit pretty hard by buying a house far away, that is indeed cheap and larger - but what happens when fuel gets even more expensive and governments issue many taxes and restrictions to discourage car usage ? (without offering realistic public transport options). Not to mention the usually poorer infrastructure/hospitals/schools
Note that it depends on the locality though, some places manage to find the sweet spot - not too far and still not that expensive. In some cities this doesn't exist.