What are the absolute highest cost components that could plausibly be in an AR 15 kit like this:
https://palmettostatearmory.com/psa-16-midlength-5-56-nato-1-7-nitride-moe-ept-rifle-kit-rear-mbus-516444983.html

The truth is, the real truth, that I built the most gucci ar 15 upper in existence and decided to downgrade to magpul furniture to look like pic related so no one wanted to steal it.
The problem is I just can't remember what parts I used exactly!

I also can't remember all the extremely expensive upgrades to the internals of my other guns. Can anyone help me remember?