This is only tangentially related to your post at all, but as a budget-conscious shopper, I've come to realize that in America, there is usually a retail shop or two locally that consistently has the best deal for a category of things. Don't get me wrong, I still have to buy from Amazon for a lot of really miscellaneous things, but I think I manage to find good local deals (better than Amazon in most cases) for most category of items I buy, more so than most people. You just have to put in the work to do the research to find where those are (a lot of times that's about going to all these stores often enough that you get an understanding).

In your example of sneakers, Adidas/Footlocker/Dicks are not the places to go for me. Here in California there is a store called Big5 Sporting Goods that consistently has incredible prices (on sale or not). In the past decade I've pretty much never bought shoes anywhere else; most sneakers or hiking shoes I've bought are under $35 and they are the most comfortable shoes I've tried anywhere. There may be a similar store in whatever state you're in.

For clothes and some home goods items, similarly I wouldn't go to brand name stores at the malls; Ross and Marshall always have the best deals. For random home goods, Daiso (an Asian/Japanese brand store) which, fortunately for myself, has a lot of stores in California, has tons of super affordable options, as it's basically a Japanese dollar store. Then there are random things that Target has the best deals for; and other random things that Walmart has the best deals for (I know, buying from Walmart is not much better than buying on Amazon).

My main point is, you don't always have to resort to Amazon for budget, you just have to do enough research work to find out where else to go.