Forget the overpriced tools is right. I saw a guy at a barber shop once using a plastic comb he probably got free at a county fair. Worked just fine. If a kitchen fork gets the job done, that's just being smart. The whole beauty industry is built on selling you stuff you don't really need. Next they'll be telling us we need a special, hundred dollar spoon to mix the color.
Read somewhere that a master barber in Japan uses a chopstick for sectioning... makes you think how much we overcomplicate things. Nathan_davis is right though, the beauty industry just wants your wallet.