To develop the concept deeper, I think it will be useful to find some documentary, because documentary are usually visible, logical, and well-directed. I searched commodity, shopping and consumption, and found 3 useful documentaries. They are
Feeding the super rich, BBC, 2015
The 80’s – the decade that made us, National Geographic, 2013
与全世界做生意（Trade with the world ）, CCTV, 2016
the first video talked about how the richest people in London live a luxury life and how people trying their best to meet their need and imagination in food and related industry.
In this film I found that the most luxury and expensive food are not actually about taste, but about the rarity and the unique story behind products.
Such as caviar, percebes and truffle.