I've just thought of a neat trick with the current Openxcom engine : It's possible to make a buildable thing that unlocks a new research project.
You can test with the attached ruleset :
- Your engineers can manufacture Weapon facility
- Once built, your scientists can research Weapon facility
- This research topic unlocks the items New Pistol and New Rifle for use and manufacture (in this example, just copies of the laser rifle and pistol)
Disadvantage:
1) the manufactured item will have the same name as research project, so you're limited to names that somehow make sense to first build and then spend some time using/studying : "gauss prototype", "particle accelerator", "plasma testbed", "psionic study module", "Global array sensor"
2) Player is not notified of new research project
3) Can't prevent from building more than one, though it's not useful.
Benefits:
1) Gives something for your engineers to do, for example at campaign start
2) Can incur a cost of specific items, for example 10 sectoid corpses
3) The monetary cost alone can make it unavailable at game start
4) These costs are visible, so the player can see beforehand that he has to accumulate 10 sectoid corpses for a reason.