Not only they are way cheaper than Rohan, but ultimately you DO create something that brings value. I am currently trying (as a hobby, though, not on a professionnal level) to set-up a homemade RC plane controller. In other word, RC plane controller is the same thing than a motherboard of a computer. It's is what will host and plug all your components (micro-controller, video, RF module, GPS, and whatnot).
I could use a pre-made controller one, but after having test several ones, I'm currently going to build my own to fit all the applications I want my RC plane to have. And it'll be home-made :P