Looking at getting into a semi auto 223 an kind of landed on a wk180c based off price point. After doing lots of looking on CGN I noticed lots selling lower wk180c recievers? I'm new to the AR platform but not new to guns an building them. So curious if it's more cost effective to buy a lower an a upper plus all the other parts? What that would entail vs a new wk180c around 1200-1300$ roughly. Thanks all input is helpful, even links or websites to more info on how they work/building one. Thanks!