Spending 1800 on a PC and using it with $10 speakers is like bying a Ferrari and putting Corolla tires on it. Speakers, monitor, keyboard and mouse are things you want to perform well since those are the things that are DIRECTLY your connection to the computer. If the CPU can to 3,000,000 instructions per second or 2,950,0000 won't matter much, but good sound and video outputs do.
Spend $30 on an OK set of speakers at least. I have seen the old Cambridge Soundworks 2.1 systems sell for about $30 or less used, those are probably the best bargain in speakers you can get.
From the parts you listed, $650 on a video card is crazy if you can't put $100 towards a good set of speakers. Get a cheaper video card and better speakers. Video card will be outdated in 3 years but a good set of speakers will sound good forever.