I agree with Proximon. you just need to decide if 15% is work the extra $685?
I would say no and put money into the rest of the system. a good OS/software SSD 80-120GB and a set of 2 or 3 of good 250-500GB enterprise raid 0 drives for a scratch drive, then a large drive for storage. 16 GBs of ram would be plenty, 8 is probably enough, but ram is fairly cheap right now. and last, but not least a good GPU. Quadro 4000 or 5000.
check out this link to some of the workstations the community has put to gether. Mine is the "Video Whisperer" it's built on a $4000 budget, and the 990x/x58 platform. I could easily be modded to the i7-2600k/Z68 or P67 platform and brought into a $3000 budget. there is also a $400 MIR on the PNY Quadro 5000 GPU right now.
http://www.tomshardware.com/forum/312821-31-bestconfigs-high-workstation
does your budget include a monitor and OS or would that need to be included?
Let us know and we will be happy to help you out.