I agree with your premise, that for someone making 500K a year a $500 bag isn't a big deal. I would argue though that most of the people sporting designer bags should be spending closer to $50 for a bag as opposed to $500.
I think it would be cool if all of those people with designer bags had their net worth in big numbers on the side of the bag.....lol. It would also work to put the number on the door panel of all Mercedes. Heh.
I would love to adopt your idea of showing income for men as well. Maybe then I can spot a rich husband to buy me a real Fendi

I must say "fake" problem is very real in everyday life. Think about it, cannot afford big diamond, no problem, get a nice CZ, cannot buy a good car, get a lease. Cannot afford designer bag, get a fake. There are so many ways to look rich and not to be one. I guess the real way to say who is rich and who is not, is by the house they live in, schools they pay for and so on. Looks are just ways to express ourselves, nothing more.