well, don't got ape on the CPU, spend money on the graphics card, ram, and then an i7 intel cpu... if you still have money left over, get an SSD because that will cut your loading times in half . and remember, the Power Supply Unit gives power to all those expensive parts you bought, so don't skimp out on the PSU, buy a decent wattage from a good manufacturer
Have a similar figure in my head.... But mines flexible by a few K....
Here's what I've been looking at....
Intel i7 920
MSI X58 Pro-E
6gb OCZ DDR3 1600 tri chan
Coolermaster Hyper N520 cpu cooler
Coolermaster HAF 932 chassis
Coolermaster Real Power 650W
Been flipping between ATI HD5850 and 5870 but with the 5850 I come out to about R13 500. A 250gb drive is included in the R13.5K just as a primary drive for me. I already have 2 optical drives (one blu ray drive) so thats not included, but add the DVD/Blu Ray drive and you should be well on your way.