I think very few people deliberately buy houses in places that flood. The devastation of water, often tainted with sewage, coming through your house, your belongings ruined and having to move out for as much as a year or more, until it is repaired, the worrying unease you live with ever after when ever the rain is heavy, is equally devastating for every one, regardless of income or house price.
Most people live where they do for reasons of finance, job location, closeness to family etc. Floods like we have had this winter are exceptional. There have been a number of people flooded along the Thames who had lived in the same house for 60 years or more and never, until this year had their house flooded. I noticed that many of the little bungalows close to the river were nearly all raised up with a flight of stairs up to their front doors, their houses were above the flood level but temporarily marooned by water round the house, it was the houses away from the river that were devastated by water in the house.
Our village has now been flooded twice in seven years. The previous two floods were 1895 and 1947. When we and most people now living in the village first moved here it was never considered an area that flooded and even after 2007 it was seen as an exceptional event and it would be another 50 years before it happened again.