There is nothing wrong about buying second hand stuff; some great condition disk jockey hardware can be found in clearance sales, garage sales and flea markets if you look hard enough. It is important though that you know how to appraise equipment and know how to test them out before you purchase. When buying major second hand DJ Equipment jockey equipment like turntables and mixers, ask the owner to test them out; check out the tonearm, the stylus (extra ones maybe great!) the table itself and check out if the belt drive works fine. Ask for an actual demo and try doing some scratching on your own. Chances are if there are turntables for sale, there could be a mixer nearby. There may also be tables and mixers in one which could make your hunt easier. Mixers must be checked for the number of outputs it has, room and booth controls, capabilities for MIDI and latest input capabilities would be great. It may be difficult to sample a mixer out for any problems but ask for any repairs done and if there are warranties left from the manufacturer.