"The Black Album" by Prince: Exceptionally rare cassette tape, rumored to fetch $15,000 or more, never officially released on cassette.
The Freewheelin' Bob Dylan" by Bob Dylan: A rare 1963 promotional cassette tape, speculated worth approximately $1,000.
The Power of Independent Trucking" by Big Black: Released in 1985, a rare cassette tape valued around $500.
"Before and After Science" by Brian Eno: Another rare Eno tape, limited copies, rumored value about $500
In a Silent Way" by Miles Davis: Scarce 1969 release, rumored worth around $500.
The Beatles" (White Album) by The Beatles: Rare promotional cassette from 1968, speculated value about $400.