Cluster warhead HIMARS missiles are effectively no cost, because these were all old munitions on the disposition list.
This was the standard ammo of the MLRS rocket system, dating to the 1980’s. HIMARS uses the same ammo as the MLRS, its just that the launcher is smaller and more mobile.
Since the US tacitly accepted the UN CCM convention on cluster munitions it has not made new ones - or since the whole thing first became a controversy. I doubt any new US cluster munitions have been made in 20 years.
BS
If they are this effective in this circumstance perhaps we Should be making more, for export use only, of course.