I'm not a fan of cost as a basis for weapon builds. If you consider the whole reason for the multi trillion credit infrastructure, the training academy's, the space ports, the dockyards, the logistic services, then the whole multi million credit ship of jump drives, hulls, computers plus software, crew, maintenance, etc etc, is all to get those few tons of weapon systems to the battle front. The relative costs of weapons are neither here nor there, if you can achieve a better result with whatever weapons you put in then you win.
It's a question also of what you destroy with your weapons. If by paying 20 MCr more you are destroying 200 MCr. of enemy ships while saving your own, then the balance of payments is in your favor.
If the weapons system is so much more expensive than the other that you're getting 2 ships to every 1 of the enemy to the battle front fine, but it's also hard to bring 1.34 ships to a 1 on 1 scrap. Deployment and likely encounter situation also plays a part.
It's a question also of what you destroy with your weapons. If by paying 20 MCr more you are destroying 200 MCr. of enemy ships while saving your own, then the balance of payments is in your favor.
If the weapons system is so much more expensive than the other that you're getting 2 ships to every 1 of the enemy to the battle front fine, but it's also hard to bring 1.34 ships to a 1 on 1 scrap. Deployment and likely encounter situation also plays a part.