I think that you all answered pablo's question well.
It will take a sh*tload of practice to be "party" dj.
You have to figure out will you be mixing CD's, vinyl, mp3's, or a combination of the three.
You have to figure out what types of music you want to play.
You have to buy a ton of vinyl or CD's.
Unless... you get on the regional or national (international, if it's "house/dance music") mailing lists, but in that case you have to already be an established DJ in a larger market area (i.e. New York, LA., Chicago, Atlanta, etc.).
Once you get proficient at your artform you can make a LARGE amount of money.
You will also be provided with FREE airfare, lodging, transportation (with a driver and/or guide), and perdium (sp?) (daily spending cash).
Once you reach the top of your game (mixing as a dj) and have put out some of your own releases (records), you could make between $20,000 and $35,000 per gig. But then again that depends on a myriad of different things.
If you get good you can make $500.00 a night or if you get overseas you can make $500.00 for every 15 minutes.
It all depends on you, your potential, your abilities and your resources at hand.
peace...
spin