The DGX also contains the 200 GbE networking and linux support.

The ConnectX 7 2x200 Gbps networking card in the DGX Spark alone is worth $700

To be fair the connectx-7 in the spark can't even push 2x200 Gbps since it is connected via 4 pcie lanes.

Technically it's connected via 8 PCIe gen 5 lanes (two 4x connections), allowing ~100Gbps per port.

Thanks for the correction. I should have looked it up; I only remembered it being somewhat odd.

Laptops will also have to contain a much tighter configuration, display, keyboard, camera, etc ;)

there is desktop variant as well