I'm still rocking my 8800gt, I usually stick to the $200 card and buy when another $200 card is 2-3x as fast. Has worked for many years although I have ridden the 8800gt train for quite some time. Great advice here.
Yep, and by the time you buy your $200 case, $200 water cooling system, $300 motherboard etc, you could have simply purchased better hardware and ran it at stock settings. If high end rendering is really a concern, you can go dual CPU as well.