I dislike them for being vapid, useless stains on the face of the earth, but the Kardashians are wealthy. Their friends and families are wealthy. So their wedding registries reflect this. None of their social peers are going into hock to get any of these gifts. Or should they have set up a registry at Wal*Mart so as not to offend your sense of propriety?
The Kardashian sisters are the daughters of Robert Kardashian, who was one of OJ Simpson’s lawyers during his murder trial. The family got a reality show, and in the manner of most reality shows, the stars became famous in a “can’t-get-away-from-it” way. Basically, they’re famous for being famous.
I was going to say that the traditional gift would be a diamond ring set in gold. Unless of course the OP isn’t the fellow marrying her?
As to why they’re famous, near as I can unravel it, Robert Kardashian’s status as a high-profile lawyer was enough to get Kim into Paris Hilton’s social circle, then people started noticing that that one girl Paris hung out with was also pretty hot, and right around the time folks were noticing this, a sex tape involving Kim got leaked out, bringing the attention on her to a focus. From there, it was all “famous for being famous” stuff like Dancing with the Stars and the reality TV series.