Minecraft at max settings plus 100fps at what resolution? i know its minecraft but my friends 670 tends to have issues sometimes, but thats more with glitches, and seeing the bottom of the world while above ground. my friends brother uses a a10 5800k with the 7660d and plays minecraft fine, so rlly ur asking for video editing since almost anything over $100 will play minecraft lol Get a 7870, cheapest one is like $220, slightly over budget but its good, or a 7850 can get for under $200.
A 660gtx will be good for its cuda cores, if the program uses them there around $200 as well
Also ur motherboard is not compatible with the 8320, either u posted the wrong one, or something else lol