Do you get preferential treatment because you are rich?

Yes, I've seen it in the hotel industry.  A rich person is deemed to be VIP and treated differently from someone "ordinary," and are often given gifts to show that they are appreciated, whereas a "poorer" person has to pay for things, meaning, in theory, that the rich gets richer and the poor get poorer.

When you're rich, you can pay for a preferential treatment

Define "rich".  Typically you get what you pay for.