Mo, to answer your questions:
Just like Suz, I have also been an itinerant half-employed teacher / artist for all my life. Except that recently, just like her, I have experienced more steady work, which means I have more money now than 5 years ago to spend on my wardrobe.
I notice that when I am "rich", so to say, I tend to buy more items at a time. For example, tops with skirts or pants, tee with cardi or skirt and matching jacket instead of each piece separately. I am surprised that I rarely buy mistakes when I do this. I still do, but to such a lesser degree I almost don't mind. And, boy, life is sooooo much easier for many months if not at least a year.
I naturally refrain from buying cheaper stuff too, when my wardrobe is well filled. I can wait longer for closet holes, because I have viable alternatives in the meantime.
Something a bit "organic" tends to happen: I'll buy that exact new item I need for whatever exact purpose I need it, it will work and I will "forget" that item. It will quietly, yet firmly enter the daily flow of my everyday life like a fish in its river, a hand in its glove. More importantly, I will not worry about it. I will not worry that it doesn't fit, doesn't match, and, interestingly, will not worry that I wear it often enough or not. Has anyone else experiences that?
On the other hand, when I am "poor", I refrain from buying what I actually need because the price tag seems prohibitive, doubled with the ongoing guilt of spending on myself. Therefore I shop sales only, waste small amounts here and there on hits&misses. I'll still have a filled wardrobe. Except it's not really filled at all. Such a wardrobe is like a deceitful labyrinth of lesser evil choices, becoming narrower and narrower as I advance, prompting to finally only maybe one or two possibilities of an outfit, if any. All the other items lie "heavy" on my conscience as well as on my shelves.
This said, sales are certainly NOT off limit to me now! I always love a good sale. I own many workhorses bought on sale. It's just that I have come to realize that I shouldn't rely on these sales for everything. In order to enjoy a sale, you first have to have a solid base.