Prices are not the "be all and end all" of this discussion. There have been many attempts to use the Rev design. WHY?? Because it works!!! Copies are just that - copies, not any new invention. I can't speak from a legal perspective, but Rev has done all the work, now others want to ride their coattails. Beware - you get what you pay for!! Any after market service after purchase? Factory backing? All they want is your money, plain and simple, after that you are on your own!
The kites last a long time if treated well. I still own and fly my first Rev, a Rev 1 over 15 years old! Take care of them and they will last.
Frames: tougher than you think! For most uses the 3 wrap frame will serve to do the job well. Handles all the beginner knocks and will continue to be of service as your skills grow. SparkieRob has the right idea on any quad - if you are gonna crash, don't pull, GIVE! That's right - GIVE! Throw the hands out, take some steps forward, and lessen the impact of the crash.
PS: most of any 2 line control method you know will go out the window with a Rev. A completely different animal in your hands controlled by moving the wrists, more than arms.
Good luck on any choices you make!