Which RTF to start with?
When you want to get into Nitro power, my favorite is the Hanger9 Xtra Easy. It is about $350, but it comes with all reusable gear. It includes a JR XF421EX 5 channel computer radio, JR 5 channel receiver, 600mah battery pack, 4 JR 517 ball bearing servos and an MDS .40 engine - all installed. All of the above can easily make the transition to your next nitro plane. Also it's flight characteristics are great. It is the trainer of choice at several clubs in the area. We have 2 that belong to the club that have been abused and 3 students are currently learning with their own Xtras. IMO this is better than the Evolution trainer. It has one of the largest wingspans of the .40 size trainers which makes it very easy to track in the sky. I still have mine and I added the optional camera mount option to take sky photos.
JimboP