Hi-Res Adventure #6: The Dark Crystal, the first adventure by Roberta Williams to be released under the SierraVenture label back in 1983, was an adaptation of the titular Jim Henson film and nowadays is a highly collectible illustrated text game. Especially when it comes in its original box, as is the case with this copy of The Dark Crystal currently being auctioned on eBay.
It's the Atari 8-bit version of the game, has been tested and is properly running and comes complete with the 12pages long instructions booklet and three 5.25" floppy disks. [Update: Apparently the poster is missing.]
Seller ships to most places worldwide.