Buji refers to anything, or anyone using or wearing, anything that could be described as being expensive just to be expensive. Buji can be used as a noun or an adjective.
Jennifer Lopez has a $40,000 watch, she's buji as hell.
I don't shop there because it's too buji.
Chicks that keep dogs in their purses are buji.
Nice Prada bag, you buji ass.