You have quite a list of "upgraded" parts there. NiB bolt carrier, $30 safety lever, $95 charging handle, $100 trigger. In general, manufacturers aren't going to make a product with upgraded or name brand parts like that, because they won't sell very well. Not very many people want that specific set of parts.
Specifically which parts of yours are light weight? I see a skeletonized trigger. Everything else just looks like a normal part to me. I just did a 10.5" pistol build using only stuff that was on sale for memorial day. Complete Aero M4E1 upper, SB brace, premuim MPI/HPT and chrome lined bolt carrier, anderson lower, transfer fee, standard lower parts, primary arms advanced red dot and magnifier and shipping for everything came out to under $900. I think you could easily swap out some of your upgraded parts for what I bought and still come in a lot lower than your $1400.
$900 my total build
- $260 subtract my red dot and magnifier
- $75 subtract the tactical pistol brace
+ $70 get a NiB bolt carrier instead of the one i got
+ $95 your charging handle
+ $100 your trigger
+ $30 your safety lever
---------
$860
You still have $500 there worth of wiggle room to buy even lighter or shinier parts.