Well if money isnt an object 20 kostura cannons will pretty much wipe out a grav well and is the best, but I kind of think you're lucky to be able to afford 1 super weapon
Yeah but if you really think about it, the total cost of any superweapon is pretty crazy. We're talking a tier 8 research, probably a couple tac slot upgrades, ect. added on top of the cost of the actual structure. But yeah I guess it's realistic if it's the one thing that'll tip the stalemate in a long game.