Would you pay for it? and if so how much?

For nPoly the problem is it is for not fast moving objects or for very slow moving objects. The over all problem is that it uses only ray intersection collision check this may make it fast but also rare usefull.
Also the build in collision responce in the collision detection and the closed source makes it even more rare useful. Because is wand to make some more from it you can't. You just have the option to bounce.

I am not trying to be ofensive here I am just saying my opinion and I may be wrong.