I see that too. For some reason that I don't completely understand (HPD might fit), Sarah doesn't get the same "highs" from ordinary things that most of us would. Where most of us would be satisfied with having lunch with a friend, being praised for work well done, a dinner out with family, buying a new outfit occasionally...those ordinary things aren't "enough" for Sarah. She "needs" (or thinks she needs) constant praise and affirmation and a jet-set lifestyle which involves designer clothes and purses and lavish parties, just to feel like she is living a happy, normal life. Except she never really has enough - she always wants more. I don't want to call it greed, although I think it is greed in a sense. But in another sense, it's an attempt to fill some kind of a void.
I feel like Sarah really does not have self-worth and if you took away all the money, the fame, and the attention, she would be left with "herself." And she doesn't like who she is. She buys expensive things, rubs shoulders with the rich and famous, and drops endless references to her royal connections, because all these things make her feel worthy in some way. If they were gone, she would be lost. That's why I think she's clinging to her past lifestyle and doesn't want to change.
She's afraid of being alone with whatever demons keep haunting her (and I think it's hard to deny that Sarah is haunted by some sense of worthlessness after watching her sessions with Dr. Phil and Suze Orman. I think she was trying to construct a sob story and deny the truth sometimes, but then there were other times when I think her tears were real).