I will never understand how clothes can cost that much or how anyone can consider spending that much. It truly is an alien world so I appreciate the explanations at the end.
Why the price is the way it is varies a lot.
In the context of the story from what the owner said they carry stuff that is solidly put together and comfortable while looking nice. Therefore the price is from the higher quality materials and quality assurance at the factory plus
brand name. In addition since these are luxury brands they're probably making fewer items, so the cost to produce is higher.
Brand names are weird and that's the part I don't get as it makes a $100 jacket into $700 for the sake of like status or whatever.
For what its worth at the prices quoted in the story you can commission these clothes to be made for you by a craftsperson.
I also appreciate the end card