To be completely honest I wouldn't have the slightest idea of where to begin.... I do know that I would rather have a knowledgeable builder explain to me on what to get, and how to build it instead of just buying a built one from a shop... I think I would appreciate it more then just buying a new one....... So any input would be greatly appreciated....... Ideally I would like to build a .223 AR-15 but I don't even have an idea of what the costs would be either.... I have a friend who gets all of his parts and such from gunbroker.com but I'm not sure how I feel about purchasing from online sellers as I have no experience buying online..... so please any input would be appreciated....... THANKS