"The NUC is a barebones PC kit, meaning that you'll need to bring your own storage, Wi-Fi, and RAM to fill it up and make it actually work. The maximum cost of the NUC depends on which components you decide to fill it with.... The final price tag of $702.99 is reasonably competitive compared to other OEM systems, especially once you take Intel's three-year warranty into account."
Except the Intel warranty presumably only covers the bits they provide and not the bits you BYO, whereas the other OEM's warranties would also cover the (provided) storage, Wi-Fi, and RAM.