There are some initial possibilities that come to mind.
1. Is it about the bling factor? Am I trying to gain social status by showing off to others? Or am I desperately chasing acceptance, trying to keep up with the Joneses?
2. Is it about novelty? Few would deny that we get a brain buzz from new toys of any variety. Before I owned a house, I used to shop for clothes because having new clothes is fun. But all too often, they wouldn’t look as good as I thought they did, or they went out of style, and out they went. Great! Time to shop for new clothes!
I think these things may be true for some people. I know the novelty motivation was once true for me. But I don’t think it tells the whole story.