It kinda goes like this .
Sure , someone could hand you a system under the table .
You go home with your bargain system , install it , make a minor mistake , call up the big Dealer for warranty on your compressor thats locked up , they ask what shop you went through ( otherwise the warranty is void )
Uhh , Then what
You have 2 choices then . Tell the dealer the truth and maybe get the fella who helped you into quite a pickle . Or call a licensed shop that does this for a living and have them come clean up your mess . But guess what ..... you think THEY are gonna say THEY installed it so you get warranty on parts ? Nope . You will be reaching Deep into your pocket , and it could take quite the labor to make it right again .
Ofcourse this never happens though
This make any sense ?