What price should i sell my subwoofer and amplifier and alpine radio?

I have a Rockford Fosgate P2D412 Subwoofer, Rockford Fosgate Amplifier P300-1, and a Alpine CDA-9886 head unit. The subwoofer is already set to go with a box and all the wires it need to preform well. The radio has a AUX head jack, IPOD head jack, and a USB head jac. I am wanting to sell all of this but what price should i put it at?