AC Current Monitor

[kevinzzz]

I'm trying to build an AC Current Monitor to monitor currents from 0.1
to 2 Amps and for frequencies between 10kHz to 100 kHz, on the
principles of Maxwell's equations.

I've seen companies selling these devices for up to $600
(www.pearsonelectronics.com). However, I'd like to save a few hundred
bucks.

Any textbooks or PDFs on this would be appreciated.

Thanks!