The two workstation nooks (spaces) have the capability to have a second monitor but I've since retired them in favor of ultrawide monitors which I find are a better experience in general. My current working solution is a split between two technologies: one thin client (second monitors) and one network distribution solution using multicast (primary displays and USB). Both run on copper 1 gig but the multicast traffic requires a switch that doesn't suck and vlan usage. On average a single port can reach 70-85% usage sustained. I believe my longest run is 150' ish.
Cost per node is roughly 300- so comparable to what you are experiencing. If I went stupid cheap I could probably cut that to maybe 150-250 depending on my luck with eBay and patience.
In terms of capabilities you could argue that this could be done without distribution using a nuc solution... but you'd have to split resources to reach node you'd need a full feature set at.
My central server is a threadripper build with 2 gpus for direct passthrough to 'gaming' vms and a split gpu handling the rest of the needs of the other systems. Thanks to the matrix capabilities any given seat can be any system... or in some cases 2 seats can be a single rig (2 room gaming off the same display). There is a cost savings to be found in splitting resources from a more expensive build out to cheaper nodes... but ymmv depending on active seats and specific needs. I believe as a general rule it should be less costly and more efficient (power/heat) than individual solutions.