Buyers have to be careful when bidding on ham radio equipment so they get all the required accessories.Frequently equipment is sold that does not include the external power supply or other accessories needed to make the equipment work properly.This is where knowledge is king.Some equipment is self contained and ready to go but older tube equipment uses external power supplies, VFO's,external crystals that only work on one frequency, sideband adapters, modulators, special microphones, remote controls, antenna tuners, phone patches,RS-232 adapters,obsolete connectors, obsolete parts and the manuals are very difficult to find.Some of these accessories can be obtained from third party vendors and on EBay by using the search engine. If you are an expert in technical matters you can get some bargains by finding equipment in which the seller doesn't know what the equipment is, the equipment needs repair, is missing accessories or manuals. You can increase it's value and put it back up for bid when you get the manual, accessories and repair it. Some collectors have fully equipped workshops, years of experience and are exceptional technicians that will rebuild a 1930's transmitter to be better than original.They draw new schematics for obsolete ham gear from examining the equipment with their expert eyes and knowledge of electronic circuitry. They frequently spend thousands of dollars on restoring a $200 piece of  radio gear but they are few in number. Most microphones, speakers, antenna tuners (except remote controlled tuners unless you build a new interface) phone patches, linears, station monitors, keys and keyers can be obtained from third party sources who have accessories which are compatible with your equipment.Your sources for information and parts are BAMA, (bama.sbc.edu) for free manuals for old boatanchors, Heathkit Virtual Museum, Collins Collectors Association and many other free websites, manufacturers websites plus your search engine.The best thing to have is an experienced ham (Elmer) who will back you up when you get in over your head.