Dominions 3000 (name confirmed!)

[Darkwind]

The gold cost will only really come in as upkeep, since the Capital Ship will be a high-tier (the high-tier) summoned ship. Besides, Earth magic is meant to represent general knowledge of construction and such (in my eyes) in Dom3K. Also in my eyes, Astral is knowledge of ancient civilizations and the ability to harness their magic or technology for one's own use. With Astral magic one could build a ship from an ancient design which appeared as three ships (glamour), or a ship with a shielding device that stopped 3/4 of all attacks (ethereal). Also, of course, summoning missiles which caused matter to decay or ancient forces that, well, killed stuff to destroy your enemies. Earth would deal with more conventional building in general (pretty much every ship would require Earth), building weapons, missiles, etc.

But anyways, Neoclidia will likely have very weak recruitable ships with the rest being summoned. Its generic large ship will likely be summoned as well.