mags are out there. and the Ishapore is a fine gun, the main difference is that it is chambered in .308 NATO as oppposed to .303 british.
as far as values go look on
www.gunbroker.com my estimate would be, in good condition of course, about 350$, if its not matching #'s and its in poor condition {i.e. the bore is not good} 250$ or less.