Misfits, Legacy of Brutality
The second pressing of Misfits' 1985 compilation album only included 16 copies. Legacy of Brutality was produced and overdubbed by the band's former singer, Glen Danzig, after he quit so he wouldn't have to pay royalties. Those 16 copies are worth $5,000 each.
Stonewall, Stonewall
The self-titled record by Stonewall was pressed in 1976 without the band's knowledge under a production company called Tiger Lily. Turns out, that company was just a front for a tax scam operated by the mob. If you do, however, own a copy, you could be sitting on $14,000.