I love this!- this is exactly what the world needs right now. Your description of constantly buying cheaper things because they are a "good deal" sounds exactly like me (which I am trying to change).
I personally like to shop online more because I am more likely to find my size, and even if I'm buying a more expensive item, I'm more likely to find a coupon I can use on it.
The other thing I'll add is that even if you're getting more expensive pieces, you can still thrift them. This is a really good option for people who still need to be on a low budget. Companies like Madewell have an area on their website where they sell "pre-loved" clothes. I guess I'd advocate for both buying less, but buying used.