I totally know what you mean!
My WIWs are full of designer pieces but they almost all cost me less than if I bought the same item at full price from the Gap. I'm pretty happy with my current balance but it took a while to get here.
In grad school (20s) I was on a very tight budget. I only shopped at thrift stores. I was still refining my style and I was happier with used, nicer brands than disposable new clothes. Nicer at the time just meant Banana Republic or such.
As a postdoc, I was barely making more money, but I found higher end consignment things or deep discounts from nice stores. Around 2010 I got a lot more into fashion. When I showed up at YLF in 2013, I had started collecting much nicer things, but still always at a huge discount.
For a while I shifted to buying too much, but I still don't buy many things full price. I think I've honed my closet to a nice mix now and I'm being a lot more cautious about what I accumulate from consignment stores.
I'm not sure I'll ever let go of the hunt, waiting for something to drop in price before I'm willing to buy it. It's fun. But sometimes I realize I should identify what I need and what will be worth the money and just go for it!