What are you doing for "home entertainment"? You may not need that much power. Kodi runs fine stand alone on a Odroid N2+. For a $100 you can get a refurbished optiplex micro with 16gb ddr4 and a 128gb ssd that'll run a full desktop plus kodi and retroarch, etc. (I use one in my living room). Storage may be an issue, but any old cpu with a 1gb nic should work as a file server. Just throw a 8tb hdd in it (or a couple of them) and call it a day. I think 1080p streams at 5mb/s if I recall, so you should be able to server a whole house even with a 10 year old i5.