3 was encased in a plastic container and is registered in a database for collectors
The original starter Pokemon pretty much dominate this list, and rightfully so
It obviously went on to be a giant hit without causing major problems so I guess you could call it an accident with a happy ending
Its value depends on the exact card, variant, visible wear, and buyer trust
Whats harder to predict is whether any of the potential Combo/Reanimator style decks will rise to consistently challenge the dominant Midrange and Aggro piles
Generally, there is the primary Cube, the worth-the-Limited-splash-big-stuff Chromatic Cube and a supplemental combo-based one, the Tinkerer's Cube. MTG Online (MTGA's much-maligned step-sibling) has Cube on the regular if you find that you really love Cube