I've recently finished a game with this mod, ended with a full type X, all weapons researched alongside most upgrades, however what struck me was what was needed to produce a nuclear warhead. 240 units of plutonium, 24 kilograms. A realistic price, but a price out of reach from all but the most ridiculously late game colonies. I suggest not to reduce the price of warheads, but to allow us to obtain them via production of Highly Enriched Uranium. It would be very expensive on the uranium end, but a quicker, perhaps less efficient, way to build nukes.