In 1.3.10, I will revise the set of buildings for these offworld trade items and use the "contract" mechanism I have described a few posts back. Once you have a space port, there is one generic building "Offworld Contract" you can build. When it completes you get a picklist of the available contracts. The following contracts are available:
Caladanian Wine (Atreides)
Slig (Tleilaxu)
Sardaukar Cooperation (Corrino)
Kindjal (Fenring)
Thinking Machines (Ix)
Opafire (Ordos)
Semuta (Ecaz)
Sapho Juice (Ecaz)
If the named civilization is in the game, only that civilization may select it. Otherwise, any civilization may select it. Each contract may only be selected once per game. Each civ may build any number of contracts, as long as there is at least one available contract when they start. Once a choice is made, the appropriate building appears in the city, and gives whatever effect the building has (for example, providing three units of the resource, or whatever.)
Suppose there is a game with Atreides, Tleilaxu, Ordos, Harkonnen and Chouhada Fremen. This means the other contracts, Sardaukar, Kindjal, Thinking Machines, Semuta and Sapho Juice are available to all. Suppose Atreides completes the first contract building. They can select any one of Caladanian Wines, Sardaukar, Kindjal, TM, Semuta or SJ. Suppose they select SJ. Now suppose Harkonnen builds a contract building. They can select any one of Sardaukar, Kindjal, TM or Semuta.
Any additional things we should put into this system?