Ok so I want an AR-15 in Nato 5.56/.223 Remington but am not sure whether I should build one or buy one. I don't want extravagant actually I want plain and simple. I have looked at the Bushmaster, DPMS, and a few others and found them on sale for around $600. My question is can I build one cheaper, or build a better one for the same money or should I just buy one for that price? The only thing I know I will add is the slide-fire stock but not right away unless it's more feasible to do so when building one. Any thoughts from you AR experts?