That all depends on what exactly you plan on doing; scratching, spinning, mcing, live mixes... Heres a list of BASICS that any DJ might need: PA SYSTEM: (if one not available at venue) Speakers (JBL powered EON series are great, pricey) or passive speakers and an amp MIXER: Two channel, multi input with a crossfader. spend more than a hundered on one. They can go up to around a thousand if not more SOUND SOURCE: this can be many things; CD players, Turntables, Mp3 players, synthisizers, samplers, laptop DJ CASE: this houses all your gear together so that your mixing will be streamlined. HEADPHONES: A good pair of isolating, full ear headphones. Sennheizer HD280's, Sony MDRV600DJ's... these are at least two choises in the $99 area. CABLES: To hook up EVERYTHING, from your sound source to your mixer, from your mixer to your amp, from your amp to you speakers, and everything in between! Other things DJ's use (no price restrictions) Subs multiple dedicated power amps compressor/limmiters Full scale sound boards (used ocasionally when mixing multiple sound sources to create a unique song) Digital delay Digital reverb projector and screens Filters MIDI devices; keyboards, synths, samplers etc... Lights Computer software: traktor, fruity loops, acid, Ableton LIVE!, Reason, Logic Pro... the list goes on. Vintage keyboards, synths: ts808, Virus... theres dozens and dozens.