As long as you have status at all, you must have constant appraisal of others' status.
I don't do this. I may value others based upon their potential impact on the world, though, on a very subconscious level; I more consciously value others relative to me. Status only matters in so much as it can achieve or accomplish something, and thus is just one tool through which one pursues a goal hierarchically higher on one's objective tree.
In doing so, they evaluate others' taste (mental abilities / fitness) and ability to afford many new dresses (resources).
Being viewed as high-status only matters if those judging have value. I understand that in the microcosm of high school, people with little world-value can be high-status, and have the power to negatively affect one's life; complying with their games makes sense in this instance. However, when those judging have no value on the scale of the game one plays or intends to play (work, mating, scholarship), then efforts undergone to have them think of one as high-status no longer make sense. In this case, buying a dress effects a net: decrease in personal funds, which I'm assuming are valued; increase in status judgment by party X, who has/have no value.
'Tis then frivolous to partake in the games of party X as 'twould only yield the loss of something valued, with no valued gains. I don't enjoy frivolity that costs me something I value and gives me nothing I value, and I operate under the understanding that neither do others. Forcing someone to make an unnecessary value assessment of: negative value of social games vs. experience of 'special event', is cruel, as it's an unbalanced choice; one knows the first negative value, but not the second. I don't think the second value can be accurately calculated using Bayes' theorem: too many variables (exempli gratia individual's personalities, inclinations, intentions, resources, hidden plans, etcetera).
I think it cruel to force one to make uninformed value calculations. In this instance, the friend plays the game on the world and high school level; she knows party X has little to no value in the world game, but does have some value in the high school game, which she will soon leave. She can't know the potential negative value of not complying with the games of party X, nor the potential positive value of attending the 'special event'. I think this forced unbalanced value calculation cruel. I am also not particularly fond of your asking such a loaded question, but I can't fault you for it.
I hope I answered your question adequately.
I don't do this.
Then you're probably going to be low status in the eyes of the vast majority who does do this. Which is a perfectly valid choice, of course.
Being viewed as high-status only matters if those judging have value.
To your friend who bought the dresses, those judging did have value. Otherwise she wouldn't play the expensive status game. This seems to me like a pretty complete answer to your original question.
You might ask why they have value to her - you haven't given the details for me to answer that. At the very least you said they are ...
The other day, someone did something I didn't expect. It was something many people have done before; something that I thought of as very normal, but that I in no way understood and had not predicted.
As I said, this had happened many time before, so I wrote it off as "me not understanding people" or "people are weird" for a second, like I usually do, before realizing that "bad at" really means "lacking basic knowledge", which I had never realized before.
And then I thought "I should ask someone who is different from me why people do that, and eventually someone will have an answer."
But many people will have many more questions like this. So, what have you observed people doing time and time again, but never understood? Or something that you only understood after a long time or asking someone about it?
And can Less Wrong tell us, not necessarily why (I for one can make up evolutionary psychology fairy tales all day if I want) but what conscious thought process occurs behind these events?