Why are front end rebuild kits so expensive??

I went to rockauto.com for a pre 73 car with disc brakes ended up being $428 for new bushings, ball joints, tie rod ends, idler arm, and pitman arm all Moog products. Add about $20 extra for lower ball joints if you have drum brake car
Probably be some additional cost for shipping and handling.
MOOG Part # K7023 Problem Solver
Front Left Lower; Front Disc brakes; $51.89 $51.89
MOOG Part # K7021 Problem Solver
Front Right Lower; Front Disc brakes $51.99 $51.99
MOOG Part # K704 Problem Solver
Front Upper; Incl. $31.79 $31.79
MOOG Part # K791
Front Lower $8.60 $17.20
MOOG Part # K408 Front Upper $19.62 $19.62
MOOG Part # K7040
Front; $22.79 $22.79
MOOG Part # K7042
Front; $25.79 $25.79
MOOG Part # K7074
Front; $62.79 $62.79
MOOG Part # ES319L
Front Inner; $35.99 $71.98
MOOG Part # ES319R
Front Outer; Incl. $35.99 $71.98
Subtotal $427.82

THANKS for this!! I have manual drum brakes (but hope to eventually upgrade to disc)