Like pucci_mama, melt977 and others have said, it's all about quality for me.
I feel bad sometimes because it's almost snobbish in a way, but i just can't bring myself to buy something that may be a nice, flattering cut/style but which is made from cheap material/fabric.
It also makes life difficult, because as a student, i can't exactly splurge. So my wardrobe, although consisting of expensive, quality pieces that i know will last the test of time, is quite small. I, like The_Ida, don't have those one-night shimmery party tops that my friends have for clubbing. My beautiful silk DvF camosile will have to do. I'm a little insecure about it because the people around me who do also love fashion (and don't get me wrong, i love watching trends...i just don't necessarily follow them) and are always in something new and 'loud.'
Shopping for me doesn't happen that often. I'm always on the look-out and i'm always wanting something (atm a Cavalli bracelet and my Louboutin pumps) but i either don't go to the next stage and buy or will thoughtlessly, as if in a trance (i kid you not) make an impulse purchase. My last were some gorgeous YSL velvet wedges. I never feel like i 'NEED' new clothes though. The pieces i have are solid ones so while i may be a little repetitious (which is probably extremely WRONG seeing as i am interested in style/fashion) they're never 'unfashionable,' or passe, so-to-speak.
The body image problems i have highly influence the rate at which i buy clothes. Although they are a burden to have, they also work in a positive way i guess in stopping me from buying some fabulous (and fabulously expensive) pieces.
edit: i feel like i just made no sense. lol.