Are you looking at the nexstar ARF or ready to fly? If you get one without the radio, you could add the 2.4 ghz airtronics and have a radio that would be perfect for your next model as well.
The fully ready to fly version has a cheapo 4 ch futaba... futaba radios are generally fine but 4 ch is going to really limit your options and you'll still have to worry about frequencies.
The complete package with the great planes simulator is neat, but you'll end up duplicating at least the radio purchase when it comes time for your next model.
Then again, that nexstar package looks fairly complete. Some of those features like the AFS stability dingus, the removable "training flaps", and the drooped leading edge airfoil extensions are pretty unique for trainers but they ought to work fine. The AFS might go wonky if it's not set up right but I suppose following the instructions ought to make it work out ok. You'll still need to find an instructor, but that .46 size nexstar looks like it ought to be a fine trainer. Assuming it's not grossly overpriced, the big question would be whether to get the ARF version (requiring a radio and engine) or the fully ready to fly version which will reduce the number of installation decisions you'll need to make.