Build it yourself and save a ton of money!
Do you already have a case? Keyboard and mouse? Operating system? HDD? What do you already have???
http://pcpartpicker.com/1XQwK
CPU: AMD FX-8350 4.0GHz 8-Core Processor ($197.97 @ OutletPC)
Motherboard: ASRock 970 PRO3 R2.0 ATX AM3+ Motherboard ($72.55 @ Newegg)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-2133 Memory ($63.75 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($59.98 @ OutletPC)
Video Card: Asus Radeon R9 280X 3GB Video Card ($309.99 @ Amazon)
Power Supply: SeaSonic 620W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply ($54.99 @ Newegg)
Total: $759.23
Reasons for parts:
1. CPU- very good for rendering and still has good gaming potential, will lower render times, is over clock ready
2. GPU- checked some benchmarks on maya, CAD, and some other programs, this card is very good/cheap compared to $1,000 workstation cards and still manages to land in some of the top benchmark spots, it's also a very good gaming card.
3. RAM- I'm not sure if 16GB is quite necessary, but right now those are on sale and they are very fast, which lowers rendering time, 2133 at CAS 9 at the price of 1600 CAS 9 8GB, what more could you ask for
4. MOBO- solid, cheap, has 6GB SATA, other good features and price are great, good reviews
5. PSU- high build quality, enough power, semi-modular to get extra cables out of the box
6. HDD- fast 7200rpm, cheap, large 64MB cache, 1TB space
A bit over budget but worth the cost if you consider how much workstation PC's cost. I can't really reccommend other gaming GPUs after seeing the performance benchmarks for the 280x, it just does too well compared to the $1000-3000 dollar cards to ignore (it costs just $300) and it even beats faster gaming GPUs in some tests. The extra price you pay will be worth it, however if you really wanted to knock $80 or so off of this build you can get an FX-6300 instead of the 8350, which would make your render times longer, but you could get an aftermarket cooler with it and OC it pretty far with a nice cooler like a 212 EVO.