Buy Now or Wait for Revision B?

[parisse]

I'm not sure to understand what you mean by porting the whole Xcas to the Prime. I guess you are not speaking of the UI, but of the giac computing kernel. The giac port is almost complete, except part of the code for fast multivariate polynomial operations (it seems it does not like proprietary compilers). The optional GPL libraries addins that you get inside Xcas can not be used in a proprietary application, you won't get PARI functions on the Prime for example. That should not be a real limitation, because they are useful for very advanced maths or giac has its own function, perhaps not as optimized, but you won't see the difference on a calc (for example I don't think many users would really benefit from PARI advanced polynomial rooter that is much faster than giac for polynomials of degree a few hundreds with integer coefficients having a few hundreds digits).