I always thought that it was more important to make the characters relate-able. If the readers could understand her, regardless of setting and circumstance, then I've met the most important challenge. I don't like Scarlett O'hara, but I love her and I totally understand her. So when I sit down to craft a character, that's my objective. The most important thing is for the reader to connect and invest in the character, and can do that even if they don't like her.
One of my favorite reader email said: I don't really have any experience with Chrissie's lifestyle, I don't get it, but I totally get it, get her, get it?
Another said: I can't stand Chrissie, but I couldn't put the book down. I had to finish it. She pissed me off, but I want to read the next one.
The human experience is the same for everyone. The rich girls just live in better houses. If readers hate rich girls, well that's OK, because if I've done my job well maybe it will end as a series of girls readers love to hate. That works too.