I don't think it's offered for export or anything yet so I doubt we can reasonably expect information on cost. But compared to conventional shells I think we can also reasonably assume it will be more expensive. The 370mm variant in particular. Carrying 8 370mm rockets each with a range of 280km, not only does it present a whole new world of long range strike against deep targets, but for Taiwan contingencies it massively boosts the flexibility and mass of fire that could be fielded even when operating multiple dozen km inland China's own coast, in turn freeing up SRBMs for other targets. It will be interesting to see which units end up receiving this weapon in the most number.