1) It is true that a real hypersonic missile is very expensive to shoot down. These are not them. Real 'hypersonic missiles" do not just travel at speeds greater than Mach 5, they can also TURN at speeds greater Mach 5. The ability to turn at such a high speed makes them very difficult to shoot down. China is NOT making missiles that can turn at Mach 5 for less than $100,000 Instead these are missiles that can reach speeds of Mach 5, but cannot significantly turn at those speeds. They travel in very predictable paths once they get up to speed. These missiles are easy to shoot down. It is true that most of the US's anti- missile weapons cost more than $100,000, but we are developing cheaper methods to do it.
2) A missile that travels at Mach 5 but cannot turn AND is made of 'cheap commercial parts' is not radar resistant and will EASILY be shot down. These are fast, cheap missiles good for attacking a significantly inferior opponent, worthless against near-peer opponents such as the US, Russia, and NATO defenses. They are clearly designed to take out Taiwan without US support.
3) Almost all missiles can be launched from anywhere. They are all designed to be easily transported. They fit on aircraft, they fit in missiles ships. They fit on trucks. That's kind of like saying 'these missiles contain explosives'.
4) The US has already developed shipping container missiles.
Generally we consider such capacity to be near worthless They are one shot ambush weapons. Good for a sneak attack, not a war. Once you use them, people look at all your slow moving container ships as valid military targets that are easy to hit. Moreover, they totally destroy your reputation. Even after the war, nobody is willing to let you send container ships to them. Suddenly your economy is in freefall.