I don't really know who came up with this, I have been trying to track it down to give the creator credit, but my guess is The Future Laboratory as mentioned by A. Caccamo in his article: The Beginner's Guide to the Luxury Industry. You can skip this post and just go to the source material, it is a good article. If you would also prefer to watch something there is an animated presentation on the subject of The Luxury Consumer Evolution too.
Unlike the above suggests, I don't think that these stages are steps on a ladder or scale, if they are more thought needs to be put into what makes a consumer move or change from one to another, both overall and per purchase. Instead I think of these as 'reasons' for each luxury purchase, the discussion to get something expensive when cheaper options are available is based on one of these five justifications - sometimes unconsciously. Overtime, a persons buying habits would show a preference for some stages over others.
Stage 1 - Acquisition of Wealth (The Show Off)
Using luxury items and experiences to show wealth and define social position
Stage 2 - Discernment and Worth (Design Maniac)
Using luxury items and experiences to show a higher level of taste
Stage 3 - Emotion and Experience (Vibrant Feeling)
Using luxury items and experience for emotional impact, or uniqueness
Stage 4 - Responsible and Aware (Leonardo Di Caprio)
Using luxury items and experience to connect with moral or political values
Stage 5 - Intellectual and Poetic (Isolated Self-Reflection)
Using luxury items and experience for self-improvement and transformation
It is cool to think of movements through the stages as a generational thing, 'new money' is flashy but long-standing wealthy families are more private. But as I said before I don't really think the stages are connected to time, they are personality based.
A lot of my friends would fit into Stage 2, they perceive their luxury items to be better made or more precise than less expensive ones, and while it isn't a show of wealth it is often still a little bit related to the demonstration of class. No better or worse, all my expensive purchases are usually connected to Stage 3 - I like to spend money on experiences and I want them to be emotionally powerful.
It is a fun concept to consider and I hope the experts in this field move further along with the theory.