There is no way a Baller like West is going to be around to see Kim at 60. She will be way over her lease miles by then.
I'll go one better than that. She's pushing 40 right now. I would be stunned if West hangs around longer than another 4-5 years (they married in 2014). I don't care how much money she has.... you know what they say about ...."“Show me a beautiful woman, and I’ll show you a man who’s tired of #$%in her.""
Plus... he's bi-polar and no doubt a royal PITA already to her due to that alone, if nothing else. I predict they'll both go their separate ways some time over the next few years.