aside from a possible full strategic resource change, I released a little mod which ensures there's more Elerium and Anti-Matter, and a bit less Durantium here: https://forums.galciv3.com/467186/page/1/#3576755

Due to constructor spam for resources I have turned resources off for maps of Large and bigger. Need those governors man, ASAP.

I'd vote for the stockpile model, too.

Actually, I'd even set it so that instead of using the accumulated resources to build the improvements you'd use the resources to feed those improvements. If the mining is at 1 durantium unit per 20 turns then make the durantium refinery consume 0.05 units/turn. That would keep it "1 durantium source per 1 refinery" but now there would be a separation of producing it and consuming it. If you run out the refinery shuts down and gives no bonuses until you have a supply again. Separating the supply from the consuming improvement would also allow you to run it for a while with an accumulated stockpile. This would open up all kinds of strategies and make possible new kinds of improvements and projects, diplomatic options, trade deals etc.

Plus, combine that with xml-defined resources and imagine the possibilities for modders. Fuel as a resource, limiting the maximum number of engines you can support. Food as a resource, acting as an empire-wide population limiter. Factories which consumer two resources and produce a third, different one. An entire industrial economy, feeding on stockpiles of stuff and then converting it into other, more useful stuff. All this is possible in the engine, provided just the ability to define my own resource types, and the ability to make them into stockpiles...

I agree with what Petri said. Ship components should never be refunded unless the ship is under construction and canceled. Buildings should have a flat cost to construct that can't be refunded unless canceled and then a continuing upkeep. I would also suggest that the resources be doled out/deducted on fixed turns instead of every x turns since the starbase was constructed or at a partial rate of x/turn. Say every 10 turns for example.

This way the player knows exactly when that next hit of goodies is coming and can plan their strategy around that accordingly. Maybe you're a bit short on cash and have a few spare durantium you could sell off. You've been using it to build some ships with prototype durantium drivers but it's turn 47 and you wont be able to spend the rest of your stockpile before you get that next tick and you're dangerously close to going bankrupt. You have a few durantium refineries but your current income rate is more than enough to power them and still provide extras for other use. You sell all of them off knowing that in just a few turns you'll get that next hit of goodies that you can use as needed. Any buildings requiring an upkeep would deduct that upkeep from the incoming tick and if the incoming amount isn't sufficient to cover the cost then your balance goes to 0 and any buildings which couldn't be supplied shut down for the next 10 turn chunk of time. If you get enough resources during that time to once again cover all the costs then the building would reactivate when the next tick occured.

This would offer another layer of strategy to the gameplay. Say your enemy has elerium defense shields on several of their planets making them far too costly to invade. You destroy their elerium mining starbase to shut down their incoming supplies. Their stockpile runs out and you now have a window of time to invade those planets while the buildings are shutdown before they can acquire new stockpiles and power up their buildings again.

I think having to constantly supply the special buildings is over complicating things. Your not necessarily consuming durantium in those refineries.  They are refineries that need some durantium to build. Perhaps they need durantium to shield some component. It's not a fuel perse

I very much like the idea of stockpiles, the same as Legendary Heroes had. It actually quite surprised me when I jumped into my first game and found out they used this particular system instead. The stockpile idea just makes more sense considering the "lore" of the game. If I mine Durantium and make ship armour with it, why would I get it back when the fleet is lost in the far reaches of deep space in hostile territory.