> “Buy more and get a discount which increases, within some range, based on quantiry”
What amazon is doing is not the same as this quote. This isn't buying in bulk. This is more kin to B&M retail shopping where you don't have to pay any upfront costs to try on an article of clothing and assess fit. Only now, it's in the comfort of your own home.
The discount would be icing on the cake, but in the realm of fashion, 10-20% off is game changer.