The bigger point is that there is a very high chance you can see VLS cells for 1/10th the cost of Arleigh Burkes.
Moreover, just 100 units of destroyer-kits for cargo ships could spike the PLAN's VLS count to match that of the USN. 500 units would be looking at 3-5x the USN's total VLS kit (30,000 VLS cells), and I'd guess it'd cost 50-100 billion for 500 destroyer kits.
A module comprising 8 Mark 41 VLS cells is ~$14 Million these days.
So 60 Cells would work out as $105 Million, which is one-twentieth the cost of a Arleigh Burke.
Of course, there are other costs such as the radar, CEC and combat management system to add.
But then again, my first guess of Chinese VLS costs is half that of the US.
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I just don't see a requirement for vast numbers of these ships, so even 100 should be more than enough.
Let's say there are 3 groups of 10 in the Taiwan Straits area.
Each group would add 600 additional VLS cells carrying SAMs. I just don't see enough incoming missiles to require more than this.
Then add a few to each port, and some for distant operations past the 1IC