Yes, you are right. Over some targets, the missile is cheaper. But over a target where you can fly freely, air dropped bombs are massively cheaper than cruise m

Yes, you are right. Over some targets, the missile is cheaper. But over a target where you can fly freely, air dropped bombs are massively cheaper than cruise missiles. In fact, bombs dropped from bombers are more comparable to artillery than to cruise missiles. Also, each bomb can be much more powerful and be dropped with much better accuracy than most artillery. Against targets that are well protected by enemy SAM's and fighters, the equation changes, as you correctly state. Flying F-16s direcly on top of S-400 batteries doesn't make much sense. But then again, the S-400s themselves are not free, and if you can destroy the air defences at a cost that is lower than the purchase cost of those air defences, an air campaign is still worth it, even if it may need to be delayed until the air defences are taken care of.