The answer to your question is it depends on the person. If we are talking the well off, above upper middle income (let’s say for arguments sake, household income is in the upper 6 figures and beyond). I am not rich, merely upper middle income, and I don’t exactly shop in designer boutiques, nor does my wife, but I also can appreciate well made clothing that yes, is expensive. There are some high end labels that are made to impress with their name, but they are made in the same sweatshops using the same material as expensive brands, there are those where the quality of the material and craftsmanship make them stand out. If someone is wearing a good looking outfit, will ask them about it, compliment it, and maybe ask about it, but it is because it stood out.
And I agree with what someone else said, the kind of posturing the original poster is talking about tends to be among what they used to call the Nouveu Riche and the like (think the Housewives of Beverly Hills or worse, NJ), where they are very conscious of things like what handbag someone has or what dress they are wearing or what car they are driving, not because they necessarily know good fashion or quality or appreciate it, but because they know the cost and judge things based on that. The whole “Darling, is that Prada” kind of thing is common with people like that (and you don’t have to be rich to be like that, plenty of people in the middle or upper middle income see something someone has, and instead of saying “wow, that’s nice” say “How much did that cost?” kind of thing. My son went to a private school that had a lot of families that would be perfectly at home on the real housewives of NJ, lot of them were second marriage trophy wives of guys who were corporate executives, corporate lawyers, etc, and the families had that kind of attitude, judged people by what car they drove "Oh, you drive a C class Mercedes? How gauche…needless to say our slightly battered minivan didn’t even register). There were people there who were old money, the kind of thing like they were patrons of the local big steeplechase even, and while they wore really nice clothing and drove expensive cars, I didn’t get that sense out of them (then again, when the husbands and wives opened their mouths, you heard the tones of private schools and such, many of the other type I am talking about talked like the women on “Real Wives of NJ” or Jersey Shore).
My mom once said something about those kind of attitudes, about label consciousness and such, and she said she thought that attitude was expressed by people who weren’t born into wealth, and grew up assuming that is how rich people acted (like the gray poupon commercials:). You run into that in car collecting circles, there are people who are all caught up in the price of a car, and many of those who are are the ‘nouveau riche’ types, whereas the guys from well off backgrounds tend to be very unassuming about their collections and love nothing more then to talk about the cars they have, about the attributes of the car, the unique features, they tend to love the car because they love the car, not because it has a 6 digit or 7 digit price tag.