With two CAT-6 cables, you can run HDMI and USB-2 (to a hub for keyboard/mouse) a fairly long distance with the right extenders:
(Note that one reason the HDMI costs $300 is that it does not compress the video; the $30 ones you can find have much longer range, but will use compression).
1: https://www.pulse-eight.com/p/185/neolite-hdmi-extender-set
2: https://www.amazon.com/Monoprice-Extender-CAT5E-Connection-1...