If you do not already have a nice radio that you can just buy a receiver and servos for, the Cessna would require a 4 channel radio, which comes with receiver and servos $100-$125 or so, a motor $45-$50 or so, a ESC $35-$40 or so, a LiPo battery $50-$60 or so, and a charger $45-$60 or so. It is a more expensive option going this route obviously, but well worth it if you are going to be in flying for a while. For another $30 on the radio you can get a nice 6 channel that has all kinds of options for the future. Once you are done with everything, prop selections, misc. including the plane you will be around $400.