I’m torn badly with Amazon. After read The Everything Store, and what has been written all over the place, Jeff Bezos is a massive turd. Employees are horribly treated, wages suppressed, and all sorts of terrible and abusive practices. Then it comes time for me to buy something. I needed a new pair of size 14 sneakers. I drove to Adidas, Footlocker, dicks, and a few other stores but I just couldn’t justify $100 sneak…
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.