But, the difference in autonomous and none-autonomous are just a processor and a GPS right?
Cost is an important aspect for a lot of people. $500 might be on the nice side for really being into the hobby. But it's on the expensive side for me.
I've build a model sailplane, model spirit, 2 meter width, build from scratch with just the drawings. Cost me about 50 euros excluding the electronics. Electronics set me back 200 back then. But most likely cost less then half that right now. As the price of those parts dropped significantly the last 10 years. Think you could build it for less then 150 euros right now.
But because of this, I also know people that easy spend 1200 euros or more on a sailplane. So it's important to know what your goal is. Do you want a cheap printable/expandable quad-copter for people who might want to get into the hobby, or do you want a high end machine with all the bells and whistles?