I shared a nifty 1967 Topps Who Am I Proof Paul McCartney card the other day; on the same page of the auction (two lots later) was one of the remaining unopened boxes!
It remains a pricey box; REA sold one for $5925 in their Spring 2013 catalog.
More recently, BBCE offered this one on their site, which they authenticated, for $29k.
For completeness, here’s a wax wrapper.
Check out The Unopened Archive for more!