UPPER RECEIVER:

Aero Precision Upper without forward assist  – $100
Geissele Super Charging Handle – $90
Faxon Barrel Perm Flash Hider, 14.5″ PENCIL, 5.56 NATO – $260
MWI Low Profile Gas .625 block – $40
MidLength Gas Tube – $16
Faxon 13″ Carbon Fiber Handguards – M-LOK – $340
Bolt Carrier Group – $145
Holosun H503C Circle Dot RDS – $200
UPPER TOTAL:   $1191 (approximately)

LOWER RECEIVER:

GWACS Polymer Lower – $129
KE Arms SLT1  – $200
KE Arms Safety – $35
JP Silent Capture Spring – $130
Norgon Ambi Mag Release – $90
PDQ Lever – $60
(You will need some springs and bits from a traditional Lower Parts Kit to complete the build).
LOWER TOTAL:  $650 (approximately)

OPTIONS:

Magpul M-LOK Polymer Rails
Magpul AFG – $34
Vortex 3x Magnifier – $199
LaRue Magnifier Mount – $162
Viking Tactics 2-point Sling – $50

Variable Optic  (in lieu of RDS + magnifier):
Trijicon TR24R: AccuPoint 1-4×24 Riflescope w/ BAC, Red Triangle Post Reticle, 30mm Tube – $860
Aero Ultralight 30mm Optics Mount – $63