When I go shopping DF or otherwise, I look for items I want to buy . I don't random buy because it's the cheapest mainly because I'm not interested in it. Invariably what I want to buy is not stocked. As I walk through DF I see the odd item whose price on the high street I'm familiar with and invariably I do not find the price compelling. Often more expensive. My shopping does not extend to liquor or cosmetics though I did drink a nice bottle of Sonona County (not into spirits Whisky) in Colorado and thought I would see if it was a DF stock. Unsurprisingly it wasn't.
I don't avoid DF (I think I said I don't do DF), just not interested in it generally and my suggestion is to avoid them. But I do occasionally look for specific items. And generally look at the price of Bose QC headsets to confirm my biases.
people can spend their $$ any way they wish and so I wish them luck, but I don't believe it's a good value proposition for me.
My best bargain was in NYC non DF. Calvin Klein suit perfect fit and 75% cheaper than exact same one in DJ. $$ saved about AUD$700