This is something I would love to see in this game.
What do I mean by quantified resources? I mean strategic and/or luxury resources that are mined from various locations (planet/starbase/star?/etc) which accumulate. So I have a deposit of unobtanium on my planet, I build a lvl 1 mine there and get 1 unobtanium per turn. I can spend 1 unobtanium to build 1 piece of unobtanium armor on a medium hull ship, or 1 piece to build unobtanium rocket launchers on a large ship. Luxuries could be used for things like happiness, farm efficiency, or even some drug that improves research. Ginseng research lab improvement, consumes 1 Ginseng per turn, provides increased research over basic factory as long as the Ginseng flows, less then normal factory if there is no Ginseng available. Hell you could even come up with something like Spice from the Dune universe that allows for faster space travel when consumed or some kind of spice induced visions (aka scouting/intelligence).
The resources accumulate every turn, more is obviously better since you'll be able to build more fancy ships and other malarky. This also can tie in with diplomacy as trading finite resources could be very profitable.
If you wanted to get really fancy you could tie in implications with mining planets being blockaded, though I'm not sure how the details would work for that.
Basically having resources to manage besides money, hammers, food, and beakers would be really interesting to me.