At $200, a Pi Plex setup probably isn't what you need.
One great way to put a spare SBC to good use is to make it a server of some kind. After all, they're really good at staying online for long periods of time, and they use barely any electricity, so ...
Today the Raspberry Pi Foundation has officially launched a new accessory for the Raspberry Pi zero and larger Raspberry Pi mini PC in the form of the Raspberry Pi TV HAT or rather Raspberry Pi DVB TV ...