So, I'm working on my first AR build, and the main objective is to build a rifle under, or at least close to $600 (this doesn't include sights/optics). So far, I've got a complete lower and stock for $145, and now I'm trying to figure out the cheapest way to get a complete upper and bolt carrier group. After hours of looking for parts, the best I can find is a complete upper for $400, but these don't come with a BCG, which will cost at least an extra $150, which completely kills my goal. I tried finding the parts separately and I figured the parts to be even more costly. Am I missing something, or was this just an unreasonable goal?