A lot of you guys have a wealth of knowledge and experience and I appreciate your willingness to share it. Any DON'T DO'S associated with purchasing AR uppers or lowers in quantity? Obviously one needs to be certain of the quality of the parts, pricing etc.. The reason I'm asking is that the prices/values of guns and ammo are climbing along with inflation, rather than static like our paychecks etc.. I have some extra investment dollars and I like diversification. Seems like a realistic place to park some bucks. Any advice? I am not looking for generalized investment advice or a discussion of brand names; only advice as to what to do, not to do with the actual purchase details. ATF red flags, "crap, I wish I had done it this way" type things.