 Though Raymond and Martian live in something comparable to a castle, Raymond "turns his nose up to it."  This shows that
"He's dissatisfied with the current social order and killing you is part of an elaborate plan he's formulated to change it. Martin was told to call him Uncle Raymond. The non-glass part of the house was of neat, natural-toned wood, with a neat green lawn in front and a neat parti-colored garden in back. "And Conrad really got upset over the way Earth has been exploiting the not so intelligent life-forms on the other planets," Raymond continued. And, on those worlds, it's far cheaper to use native labor than to ship out all that expensive machinery.
 for the people from the future, regardless of its grandeur, nothing in the past is good enough for them.
 for the people from the future, regardless of its grandeur, nothing in the past is good enough for them.  in the past, class was determined by what you had to show, and in the future, it is based upon who you are as a person.  Materialism doesn't exist in the future.  Raymond's purpose there is to show Martin the finer things life has to offer above any other purpose.  in the future, people have taste, whereas people in Martin's time do not.