Yes, how much money you earn has nothing to do with being upper class. Upperclass normally comes from the social position of your family and not from your own achievements or wealth
Britian is a country where apparently the class system still influences the way people think. But it's already changing, otherwise William wouldn't be dating a girl like Catherine.
Or here in Germany: my aunt recently died, well, she was not my aunt direct but my mother's cousin. But I attended her funeral anyway. Her grandfather had been a nobleman, owner of a grand estate close to Berlin. When her father left her mother, her mother with her infant daughter returned to the estate of her family where my aunt grew up in close connection with her relatives. But then the war was lost, her grandfather dead and they had to flee, my aunt being a student back then. The estate was confiscated by the communists. So they had to live in one bedroom and living-in kitchen in an appartment shared with 3 other families (including sharing the bathroom) in Munich. My aunt studied while working to support her mother and grandmother for the rest of their lives. She got a little bit of help from her cousin, a countess whose family had fallen on hard times themselves due to the wars.
My aunt was just a normal teacher, supporting her family and being able to buy the half of a semi-detached cottage in the Greater Munich area. But when she was buried, even the doyenne of the noble family attended the funeral, small and frail in her wheelchair, surrounded by those of the family resident in Bavaria. Was my aunt middle-class or upper-class?
I don't think it's that easy anymore to put people in their "class" from the fact of their birth. It may matter much more eventuelly how they behave, IMHO, what kind of overall ethic/character traits they got from their ancestors/millieu and how they personally put their background to use in their own life.
Even the upper class in Britain has been known to embrace people if they behaved like a true lady/gentleman, their pedigree no issue then. And to shun people with the best pedigree if they behaved abdominally. Yes, of course, according to the rules of a given time, but still.
So the question of Catherine being rich or pedigreed should not matter anymore today, as long she herself, as a human being and a personality, is embraced by the highest ranks of a country which still has ranks and orders of precedence. We all know how Charles fought to give the love of his life the place she deserved in his opinion in the pecking order of Britains Precedence-system and I have no doubt William will follow his father's example once the day comes for him to make his decision public.
