In Europe, the prices, with all taxes included, for an Intel NUC Pro with Raptor Lake vary from around EUR 400 for an i3 CPU with 16 GB of DRAM to around EUR 800 for an i7 CPU with 64 GB of DRAM.
Similar Chinese computers are cheaper. If one searches for a Mini-ITX MB with at least the same number of peripheral interfaces as a NUC and one adds the costs for a CPU of similar performance, for PSU, case, cooler, DRAM and a small discrete GPU, to match the performance of an integrated mobile GPU, it is impossible to build a significantly cheaper computer.
Some economies vs. a NUC can be achieved only by building an even larger computer, with a microATX or ATX MB and by omitting some of the interfaces provided by a NUC, e.g. by not having any USB 4 / Thunderbolt interfaces.
A complete NUC-like computer with a slower Alder Lake-N CPU (e.g. Intel N100) can be found at less than $200, which is a price difficult to match with any bigger computer.
Some people like to point that there are complete laptops that have the same price as NUCs. Nevertheless, those laptops are garbage that I would not use even if offered for free. A NUC is much faster than most laptops that seem to have the same components (due to better cooling) and it has more peripheral interfaces that are also faster. A laptop that matches in features and performance a $800 NUC has typically a price of at least $3000 and it is marketed as a mobile workstation or as a top model of gaming computer.