[Fyron]

It's generally a bad idea to spend more than about that $800 on a (custom built) system (assuming you don't do something silly like waste $400 on a new monitor when you already have one from your old PC)... There is no real need to buy the latest and greatest CPUs and video cards when their performance gain over their half-priced breatheren is practically negligible. All of that more expensive will depreciate in value tremendously by the time the $800 machine starts to feel dated. But by that time, you will be able to get away with just updating a part or two to get the performance back up anyways.