I tried once to chart out what materials would be needed to make trade goods and from there what goods would be needed to build vehicles and ships. You can fairly easily come up with the total tonnage of electronics required for a ship's sensors, but what is needed to make the electronics? Some mix of common and uncommon raw materials, precious metals, and polymers, plus possibly a bit of crystals & gems would be needed. Deciding how much of each goes into a ton of advanced electronics is a near impossible task.
An abstract system assuming that some percentage of a machine's final cost goes into it's manufacture would work best. Many game systems set that value at 50% of the final price. While that may be fine for simple items, more complex items have lower profit margins. I have been out of the business for many years now, but aerospace companies typically had margins of 10 to 20%, so a ship might cost 80 to 90% of the final price to make.
