Slapout:

I am not so sure the Saturn 5 was either simple or inexpensive. There were a lot of parts to that thing, like thousands and thousands. Plus it was liquid fueled so it took days and days to assemble, transport and fuel. I don't remember but there may have been restrictions on how long you could leave it sitting there fueled and ready to go. And there was a huge infrastructure needed to support it. Liquid fueled rockets make a cumbersome weapon.

Anyway we could go back and forth about relative expense for a long time and not resolve it. I for sure don't know enough to do so.

True our enemies are developing missiles; but the reason those missiles vex us is because they may be used for throwing nukes. For throwing nukes, nothing beats a missile. I don't think we would very worried about North Korean or Iranian missiles if they were only going to deliver h.e. warheads.

The US has a rather different purpose in mind, and airplanes can often fulfill that purpose better that missiles.

As far as arty vs. CAS, people like Cavguy have the experience that makes their opinions really count; but as a civilian who only knows what he's read, CAS has some real value to it.