I'm doing a trade with a guy who has a AR-15. I'm new to this type of firearm, so looking for some input from more experienced people. PSA lower, RK upper. All magpul MOE furniture. A3 flat top upper with rear BUIS and an M4 front sight post. Sightmark Z reflex sight. Vortex flash suppressor, Tapco single point sling plate, MOE picatinny section under the fore grip. Shoots .223 or 5.56. Was built last summer and has only been taken out 3 times with maybe a few hundred rounds put through it. Now, pretty much all of this sounds like a different language to me, so I'm just quoting the information he sent me. I'm trying my best to educate myself more on AR-15's but there's so much to learn that it's (at times) overwhelming, so I'm calling out for help. What I would use this AR-15 for? I'm a new prepper/weekend shooter (if that). Would love adding more things to it later down the road but for now, I'd just like to know if the upper/lower are a good setup and you would value this specific AR-15 at from a private sale? Any feedback would be great.