If you look at the lessons the US is learning, here is their procurement plan (copied from the US thread)
864,000 155mm rounds
12,050 #Excalibur rounds
12,000 #JAGM missiles
700 #HIMARS launchers
1,700 #ATACMS missiles
106,000 #GMLRS rounds
2,600 Harpoon Missiles
1,250 Naval Strike Missiles
3,850 PAC-3 #MSE missiles
5,600 FIM–92 #Stinger missiles
28,300 FGM–148 #Javelin missiles
5,100 AIM–120 #AMRAAM missiles
5,100 AIM-9X missiles
950 #LRASM missiles
3,100 JASSM missiles
1,500 SM-6 missiles
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The most notable one is the 106K of GMLRS rockets @ $100K each. That works out as $10 Billion.
Also note that the US already has an inventory of 250K JDAMs @ $25K each, which works out as $6 Billion,
These are the sorts of numbers that the Chinese military would need to deter Taiwan, Korea or Japan from joining the US in a war against China.
But rather than huge numbers of JDAMs, I think they should mostly buy the Shaheed @ $20K each. You can think of it as a cruise missile which is very slow, but which costs less than a JDAM. Or as a JDAM that can fly to the target by itself, rather than rely on an aircraft to drop it over hostile airspace.