Had the same kind of problem with every brand of motorcycle i've owned ,so it is not a ktm specific one !! If you own an older model bike a euro bike is a better bet than a japanese one as far as getting parts goes ..i have seen parts no longer avaible for jap bike as new as five years....very bad indeed !!
The euro seems to think a offroad bike can last longer than that,and if a parts is no longer avaible from the manufacturer you can fall back on the original supplier,you can do that to have cheaper parts too!!:)