In order to answer this question we also need to think about industry.
What can be manufactured?
How easily can it be manufactured?
Are there any scale efficiencies? Does the cost of producing a product lessen drastically when you increase the size of the manufacturing process? (eg. at one time publishing was dominated by large publishing companies that used huge presses, but now we have digital printing, so print-on-demand is cheaper unless you are printing something in very large quantities.)
Realistically in any space opera game, very few raw materials will be interstellar trade goods. Although you could always invent something, unobtainium but with a less insulting name.
In a highly developed nanotech world, only information will be an interstellar trade good.
With less nanotech, organic luxury goods would still be interstellar trade goods. (eg. real champaign, Greek olives, Ethiopian coffee, Chinese tea, etc.) Some organic luxury goods could be interstellar trade goods twice, like chocolate. I'm sure Dutch chocolate is grown in some tropical place, brought to Europe to be made into high class sweets, and then shipped out to still other places.
Even with little or no nanotech, certain items might become so easy to produce that they are always made locally. If computers in your setting are gold ink printed on cellulose sheets and then glued together to make sandwiches, maybe that kind of technology exists at anyone's desk, so computers, AI, robots, all communication tech, etc, none of that would be trade goods.