Whadda Ya want?
Our questions are both triggering to many.
You want an AR to hunt coyote to a couple hundred yards, shoot for fun?
Go to PSA and pick the upper and lower that you like. There are possibilities for a $450 gun there right now.
You will get a gun that works and probably shoots better than needed for
those uses.
You won't get one built from the most awesome indestructible parts
made by man or God.
If you need or want a gun that you brag about to the "Operators", one
built out of top tier parts, you can save money building it yourself.
Especially if you buy it over time, carefully shopping the parts.
(Don't own one of these, would if I was buying one to use as a LEO or such)
Mid to lower level, you won't save money on a single build after buying the tools to do it.
Think of them as a M-700. Honestly evaluating it.
Millions made. Lotta BS thrown around about extractors, bolt handles....
Things that happened, but way over reported.
The Marines address those issues building their sniper rifle from a 700.
To make it as reliable as possible. Makes sense.
Personally, I know of more people using that rifle than any other bolt action.
None have broken an extractor or bolt, that I'm aware of.
Taking one of mine into battle, probably get the handle welded and an M-16 extractor installed.
^^^^This^^^^
You question really has no hard answer.
Visit "Anderson Rifles" in Hebron, KY. I've built several AR's with their uppers and lowers. Lowers can be as cheap as $50 or less. Bought 3 years ago for $39.95/ea.
For me, a DIY build runs +/- $700. Academy, WalMart, Atwood's, etc, sell equivalent AR's for less.
You can spend a couple grand buying high grade pieces/parts and still not have a shooter....or pay peanuts and get a real tack driver. You never know until you bench it the first time.
If there is any one "piece/part" that's worth spending extra for, I'd say it's your "fire group" (trigger assembly).
Best I can tell, money spent on a Giselle trigger group is worth the cost.
CMMG, UTG and cut rate trigger groups work just fine, but a "sweet" trigger seems to make everything else come together a little better.
The "best" shooting AR I possess has a $58.95, heavy, spiral fluted, .223 Wylde barrel I found on sale......but I'm a cheap skate! LOL!
I've worked around and with gunsmiths for a long time. I would love to have picked up the trade "way back when"! 😖 ....but I didn't!
What I "DID" learn in a gun shop was when to back off and say. "I can't do that!"
Building (assembling?) AR's scratches my "wannabe gunsmith" itch! 😉👍