FPV
(FPV)
3
Parts of a product combined (+ shipping) pretty much always cost more than a finished product. Just look at car parts, the sum of all parts is more than a regular car (with good lease or discount).
A low cost product like a flashlight is cheaper assembled - I was planning on building my own quad mini flooder and the parts were way more expensive than just buying the D4 on intl outdoor (especially now since they are on sale as well).