I can build a Reliable AR for under $500.00 But that is because, i can go to my local Gunsmith that i have a great relation with and pick up a LRB striped lower for $80 bucks out the door tax and transfer included... and then i can order a complete parts kit for $419.00 shipped... that puts me at $499.00 even... but it is stock funiture and NO REAR sight... so after the cheapest $30.00 + tax UTG Standard rear sight... that puts me over the mark at right around $531.50
i Can do this but you cant... You see i would have to order a complete Parts kit from a very frowned upon company that i wont mention the name... becuase they have a very bad rep... the kit Come with a complet Upper pre-assembled and a Lower parts kit and a buttstock assembly (everything but the stripped lower)
But if and when i have ordered from them in the past... i completely take apart the completed upper, and i inspect everything to make sure everything is good to go.. i then hand lap the unchromed lined barrel, i lap and the upper reciever, and polish the bolt carrier race ways and rails, and true the reciever, and then restake the gas key on the bolt carrier, polish the gas tube, and then i re-assemble the upper reciever bedding the barrel to reciever, the lower parts kit on this cheap kit is ok.. but i have had a little trouble with the roll pins so i have to adjust them by squezing them and stoneing them a bit to get them to go in with minimal problems and then i do a triger job to get the trigger pul real nice and smooth...
So you See in my Opinion in order to get this cheap complete parts kit built up into a Reliable dependable Rifle... there is alot of Attention to detail things and it is way more involved than your standard build up... THERE FOR IT IS NOT FOR A FIRST RIFLE BUILD... and Even then after all that work, you would still have a rifle that people would turn there nose up to... so i DO NOT RECOMEND THIS...
the Best advise i could give to you has already been giving:
GO WITH THE PSA KIT... you will not be disappointed, and you will end up with a rifle that will be dependable, and very well respected..!
HOWEVER, i dont want to mis lead you... you will be able to build a rifle for around $600 - $650 with PSA but you are going to spend alot more, by out fittng it...
becuase eventually you will want optics and a sling and a case and more magazines and then there is always ammo... and more ammo.. so be prepared to spend some $$$$