Yep I was done 3 AR's ago.
This.
@blues7 I will laugh because I was in the exact same spot a few years ago that you are at right now. I was done upgrading and putting parts on my Sport, it was perfect, I'm all set!
Then one day I thought....hmmm.....I really want a Colt, you know just to have one. What happened then? I found one on sale with a price I could not refuse. So it starts again, of course I had to add parts to that one too. But finally, it was perfect, outfitted just the way I wanted.
Then I got thinking, boy, I'd love to have a .300blk rifle, you know to maybe buy a supressor one day. But the cool thing is I only need an upper since they use they use the same .223 lower. Guess what, I bought the .300blk upper, got a great price too . Then I got thinking, I really need a lower for that upper, I mean it just looks lost without a lower. Then I thought, hey, this would be the perfect time to try building my own lower. Guess what, I built my first lower. I was all set, really I was! This time I really mean it.
Then Primary Arms had the stones to send me an email ad where all their Noveske uppers were on sale, how dare they! Guess what......yup got my Noveske upper in on Friday. Well now I'm halfway to a real Noveske, guess I'll have to build a Noveske lower to put that uppon on top of.
Anyway, short story long. You are never done, and you'll never own just one AR. Accept your fate now, it will be easier. Oh, and as others have said, just wait until that suppressor bug bites you too, that's when it gets expesive!