I need to sell my computer and dont want to be dooped when I sell it, what is the value of my computer.?

I do not have a mouse with the computer. The computer is a Dell 8100 limited-Intel P4, 128 mb ram, 3 1/2 floppy, samsung cd-rom sc-148c, 32mb NVIDIA Geforce 2mx, Monitor-Dell m991, Creative sound blaster -pc164v, 37.2 GB harddrive,Harmon/Karden speakers.