A neutronium cube, if again my math is correct, is an 80,000 HD construct which I'll round off to about ECL 26,000/CR ~17,400.
It would have a construction cost of 1,737,300,000 gp... let's see what else I can infer...
Hmm.. not much, but now I'm curious. I want to see it made. I think I have a...