Surplus IT equipment market pricing

I’m currently working on a project to surplus our legacy IT equipment. Currently that would involve PC equipment such as laptops, desktops, and peripherals. Later would come servers, network devices, and possibly SUN UNIX systems.

Does anyone know of a good,reputable source for obtaining market pricing for legacy equipment so that we could price the equipment at today’s market prices. Granted most will be very low dollar, but I need to start somewhere, and with a source that is acceptable bya Finance group.

Thanks!