How can I reduce the price of this rig but still keep up its performance?

if your willing to cut a bit on the raw power you can switch to a 550 watt PSU, which should cover your system. Also you could switch motherboards to a DDR2 rather then DDR3, which will also lower the price, or switch to an AMD system which is generally cheaper(because of the motherboards i've found). though really it depends on what you are willing to sacrifice in terms of performance (though you claim otherwise)