Are there any boxes without a graphics card or at least with a primitive one? So that they would be more economical in case you only need them for the role of a server?
None of them have a dedicated GPU, just a low-powered one built into the CPU. Using a CPU without an integrated GPU would only shave a few dollars off the cost, so I don't that is a common choice.
The weird extreme range (not really Nucs in my view) have a pci slot, seemingly for a large graphics card. They’ll take an SFP card though, and that’s a excellent, though probably the most expensive mini server one could buy.
All the small Nucs just use an iGPU. Boxes like the Nuc 8 have a bit of a cult following as the iGPU is surprisingly powerful. It’s probably beaten by newer models now. The newer ones have lots of cores, and when fully loaded with memory make a handy little box for VMs.
