You'd see a whole lot more of them and the game's balance would be broken.  No need to build carriers anymore; people would just build the strikecraft carrier capital ship.

The most i ever seen people use is 3 capitals in a 3 hour game and in about 4-5 hours maybe 5+.

Making it cheaper would mean more capital ships earlyer but i would have to see it happen in person and test it to decide if it is bad or good.

I'd still like to see Battleships used more often in Multiplayer. Whenever I play against someone who doesn't spam and uses battleships it makes it a lot more fun. I'm not sure why, maybe it's the dynamic nature of the battles, or that by killing a battleship can turn the tied in a battle.