I have a Tan 16inch .223 aero upper with an aero bcg for $450

There's a few guys on armslist and tacswap that has a few uppers. Less than $400

$325

armslist.com/posts/14476107/denver-colorado-gun-parts-for-sale--bcm-ba-mi-16--5-56-upper-

$400

https://www.armslist.com/posts/14488223/colorado-springs-colorado-gun-parts-for-sale-trade--upper

$250

https://www.tacswap.com/post/643889553cec501a460ecb02

$350

https://www.tacswap.com/post/643960dd1c86b393bca0a3e5

$350

https://www.tacswap.com/post/63f013e3737720f901187a64

I have a 12" 6.5 Grendel if that's in your wheel house? Includes the BCG but it needs a new extractor claw.