I'm trying to get myself an AR15 for under 1000 dollars, and have several ideas of how to do this. The first is to buy a used gun, but I don't know the laws for buying guns online or from other people, plus I'd rather have new parts. The alternative that I'm more fond to at the moment is to buy parts. Now there's a couple of things I need to know to do this; first, what are the rules for buying parts online? Are there certain parts that are harder or illegal to get? i.e. barrel. Also, I have a full metal M4 electric airsoft gun by ArmaLite so I was thinking that I would be able to take a few parts from this and put it into a newly constructed gun- stock, lots of lower parts, rails...all the ascetics. But This might not even be worth it as these are probably the cheapest parts anyways. So any tips on how I could get an AR15 for under 1000 dollars would be much appreciated! Thanks for the time.