RE: Nexstar vs Avistar vs Magister
The first question has to be: Are you going to have a qualified instructor? A Nitro plane of ANY kind is going to be a different world when it comes to performance and operation. MUCH to learn. With that said, I also wouldn't waste any more money on something like the Magister, IMO just another toy.
You can but a Nexstar ARF too and avoid buying unwanted "gadgets" and equip it the way YOU wish. Assembly will take a bit longer but worth the time.
BTW - I have flown/instructed on both.