Some days, I wish I could reach a point of not needing to buy clothes for a long while. Weight fluctuations, lifestyle changes, and the relentless & insatiable machine that is my life make me feel as if the wardrobe churn will never end.
However, being on the opposite side of the fence from you doesn't mean that I don't understand your perspective (or maybe I just have my own take on it). As a society, we've long programmed females to believe that
A) how we dress is very very very important, must look perfect all the time
and
B) caring about our appearance is frivolous and silly and shallow and etcetera
I say that you're a grown woman who has a right to feel both ways or not at all about it. If you want new things, that's just as ok as not wanting new things. I say do what makes you feel ok, and do your best to be responsible with any castoffs (which actually doesn't seem to be a problem amongst this community: the style exchange, donations, and etcetera are all wonderful ideas I've seen here to keep things out of a landfill)