Which image is worth $800? Which is worth $85,000?

(left) Andy Warhol, Marilyn Monroe, 1967, screen print, 36" x36", signed in pencil, verso, #225/250

(right) Andy Warhol, Marilyn Monroe, (d'apres) silkscreen, SBM Art Club Publisher, no date, no signature, no edition size

Rarity, edition size, condition, provenance, date, signature and historical relevance are some of the factors that make the image on the left worth $85,000. The image on the right is an "after" which means it was printed after the death of the artist, and therefore has far less value. 

Do you know what you own? Do your heirs know what you own?