Remember a really basic Shaheed is estimated at $10K, whilst the standard version is $20K?
Even if you halve the cost of a Pantsir/Iron Dome, it still comes to $25K
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You're missing the point.
Yes, the cost of the thing being defended justifies air defence.
But China can always build more low-cost missiles to overwhelm a smaller number of SAMs which are more expensive and slower to build.
So the defenders won't have enough defensive SAMs to prevent that the target from being destroyed.
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Let me spell out a graphic example to illustrate the point.
Say a US airbase has 25 stealth fighters worth a total of $2500 Mn.
So it is defended by 200 Iron Dome SAMs @ $50K each. That costs $10 Mn.
From the Chinese perspective, it just makes sense to build 300 Shaheed @ $20K each. That's only $6 Mn, which is 40% less that the Iron Dome SAMs. So China will have at least 100 Shaheed available when the US runs out of SAMs. I'm assuming the defending SAMs are 100% effective, which you know is being charitable.
So let's say the US doubles the number of Iron Dome SAMs to protect that valuable airbase. So that's 400 SAMs @ $50K which cost $20 Mn. So yes, it's worth spending $20 Mn to protect an airbase which houses $2500 Mn of aircraft.
But the logical response is for China to launch an extra 200 Shaheed. So that's 500 Shaheed @ $20K each = $10 Mn. And again, the Chinese side have 100 Shaheed left at the end to attack the airbase.
But China has only spent $10 Mn on Shaheed, compared to the US which has to spend $20 Mn on Iron Dome. China now has a 50% cost advantage, up from 40% previously.
Can you see how this response and counter-response will just keep continuing, where China keeps building more and more Shaheeds, until the US runs out of expensive SAMs?
And then that valuable airbase with 25 US stealth fighters gets destroyed.
