2014 Chevy Sonic Radio Help

I'm looking for help with my stock touchscreen radio in my 2014 Chevy Sonic. I did take it to a dealer to get quoted a replacement, and a 3rd party stereo place, and they both quoted me in the range of $1200-$1400, something about part of the cars computer being in the radio, and a special harness and stuff like that. I wanna know if I'm getting ripped off (which I feel I would be) and if any of you would be willing to give advice. I do know how to turn a wrench and replace parts, and have done so in the past, but electrical systems are a little above my head. Do you have any recommendations for replacements as well, that wouldn't break the bank? I do not know what other info to provide, but will do my best to put in whatever is needed.