200 USD is like what 14-15K, with that budget an HTPC that can run 4K HEVC H265 10 Bit files above 140mbps, will require a GPU that is min 10-12K, (1050 comes in to my mind) so figure out, you entire PC will not get assembled at 14-15K. Other very major and imp points to consider.
1.PC will take much more power than Shield TV
2.Much more space than Shield TV (The new Shield TV is even more smaller then the regular one, that I have, hardware is exactly same, mind you)
3.If you will install openELEC (Kodi) alone, you will only be able to run Youtube, no Netflix or APV, unless you opt for windows based kodi (which will make it a PC rather than an HTPC to be precise). In that case as well all would be browser based. Except Netflix in case of windows 10.
4. PLEX server . this single handed should be a reason enough to get shield, IT WORKS flawless and I am able to see my whole movie connection on 4G, on the go.
4. Solid GAMING .. even if you are NOT a gamer, everyone plays small android games, and SHIELD has some very very amazing time pass games.
4. Truck loads of other features in SHIELD TV. HDMI CEC, integration with ALEXA and soon with Google Home, and loads of Android TV apps
Trust me I have an HTPC as well and there is nothing my shield cannot do that my HTPC can do infact much more, and my HTPC cannot play HEVC 4K above 5mbps. Only 1080p H.264 plays flawlessly, but in shield all works...