The REEL problem (pun intended) is that good, straight, thin, flexible sticks are rather hard to find these days. Especially so for city folk. So we buy 'em. ;o) We pay good money, because somebody had to research and manufacture a good product for us to enjoy.
I don't currently own a Tenkara Rod, but I've certainly had fun many times fishing the same way Tenkara rods are used. I can appreciate the allure.