Well lets say you find 17" monitors with DVI (not too likely for that price btw...) and for the sake of anyone with non-failing vision, you end up with 1280x1024 monitors - 1.3MPixels/frame, 60Hz framerate. DVI is typically 8 bits per color, so 1.3M * 60 *3bytes = 234MBytes/second.
Now, unless you happen to have a semi fab/asic design team backing you up, this will require a $20-$30 FPGA attached to a $5-$10 DVI serialization chip. Oh, and that custom gigabit ethernet interface is kinda pricy too - $20 for the PHY chip, and that FPGA is now a $40 one. Throw in another $20 of memory for the frame buffer, and you'll have a reasonable estimate for the expensive parts. The power supply parts, boards, case, misc parts will take that price and quadruple it. Oh, and you'd better pay whoever is designing and building this thing, as well as the FCC/UL/CE testing, marketing, etc.
Now if you look around the web a bit, you'll find someone who had a similar idea, but implemented it in a more pragmatic way - take a half dozen video cards and throw them into a computer. Ditto with a bunch of USB mice and keyboards. Throw in some software which binds them together properly - and presto a software solution to the problem.
https://linuxgazette.net/124/smith.html
A work environment that's a bit *too* personal for my tastes, but hey, some people like it that way...