OK, I have a buddy that just bought a complete lower and a stripped upper. I am trying to talk him into selling the stripped upper and buying a complete. This is his first AR and he has a friend that said he could put it together. I am unsure of his gunsmithing abilities, another reason I am trying to get him to buy a complete. Do any of you have a parts list or a link to a parts list to build an upper. What is an estimated cost difference of building one vs a $400 psa upper? Sorry building an upper is completely foreign to me, I have only built a lower. Any help or direction would be greatly appreciated.