Interesting info from comm chatter (ED forum). There are rare commodities, which represent products which can only be created in one specific star system.
Bast - White Hart Lane - Bast Snake Gin
Chi Eridani - Steve Masters station - Chi Eridani Marine Paste
Delta Phoenicis - Trade Port - Delta Phoenicis Palms
Eranin - Azeban City - Eranin Whiskey
Ethgreze - Bloch Station - Ethgreze Tea Buds
Hecate - RJH1972 - Hecate Live Sea Worms
Heike - Brunel City - Ceremonial Heike Tea
Lave - Lave Station - Lavian Brandy
Thrutis - Kingsbury Dock - Thrutis Cream
Toxandji - Tsunenaga Orbital - Toxandji Virocide
Xihe - Zhen Dock - Xihe Biomorphic Companions
Apparently, their value increases in direct relation to the distance from that system, maxing out at aroun 20.000 CR per unit. I will for sure look out for them, but I won´t go specifically hunting those which are already on the list in this thread; chances are that a lot of CMDRs are already treading this mill. But good as a fall back option the information is valuable.
This is a nice example which confirms my "ethical" stance on "secret" information; do not keep it secret. Instead, get your share and then pass it on, like a chalice of excellent wine you want to pass around the table. Herne protect us. You might loose a bit of the profit at hand, but the community as a whole profits and you might be repayed a thousandfold when many others act the same way.