It's really quite hard to put price tags on these kinds of things. The main problem is it's probably worth more to you than it is to a stranger. In my experience, you'll make more money by parting it out on the E or the list. My system is similar to yours, and without any periphs, I'm pegging it right around 450-500.
If your GPU is holding strong for you, it might make sense to sell the board/CPU/RAM as a set, and keep the rest. I've once purchased a complete setup, and although I got a good deal on it (thanks jj!), I wouldn't do it again. I would, however, buy a CPU/board/RAM combo. Just my two cents.