It would be tough to estimate the equipment sight unseen and most people are not experts on vintage gear. Using online marketplaces like Craigslist, eBay, Audiogon, Canuk Audio Mart, try to find what others are selling them for.
Another option is to find a vintage stereo store near you and have them evaluate the condition and price the gear.
If I were buying vintage gear, the cosmetic condition would be important, but, I'd be more interested in the condition of internal electronic like solder joints, tubes, caps, pots, and hardware like drives, belts, relays, VU meters, etc. IMHO, take everything to a vintage stereo specialist and have it checked out. Just saying that everything was recently inspected by a specialist will help demand top dollar.