I believe the 2.4GHz radios nowadays are simpler than the old ones because you don't need to care about crystals, frequencies, long antennas etc.

You can get very simpel 2.4GHz radios with limited functions that are easy to install and operate.

In my view the main difference between a low-med-high end is functions and response time.

Most people that use the high end radios, e.g. for competition purpose, use only a fraction of the functions, so don't be too stressed by that. You quickly learn to only use the few functions that you need. Some radios let you have customized menus where you can put the functions you need, and then forget the rest.

If you are looking for decent quality radio, that doesn't cost too much, I believe that a Sanwa (Airtronics) MT-4 or the newer MT-4S is the best value buy on the market right now, quality, function and response time wise. These are mid range radios with almost high end functions and response time.

Futaba is off course quality stuff also, but their mid range radios, in my view, are a little outdated and no match for the Sanwa (Airtronics) MT-4/4S. But that is my personal opinion