What price should i sell my computer at?

I have a custom built computer with an ASUS A8N-E ACPI motherboard with a AMD Athlon 64 FX-55 Processor, 1 gig of ddr2 RAM, an NVIDIA GeForce 7800 GTX 256 mb, Sound blaster Live! 24bit card, 300 gigs of hard drive space and 2 internal DVD-RW units. I am not sure what price to sell it at. =(