As a seasoned vetran in this business i honestly tell you that yes you can make a lot of money doing this and you can make a good living but it is a lot of hard work and a painful road getting there.  There are not a lot of secrets outside of being cautious and putting your money in the right place.  I started with a couple hundred dollars and have made tens of thousands.  Here is the best advise i can give for someone to get started:

1 - Attend several auctions - study the people and pick out the veterans and watch them closely (they will never over pay)
2 - Only bid on what you can see and don't count on the wow factor (yes the shows are cool but also full of S***)
3 - SET A PRICE TO PAY (Never get caught up in the moment and never get a bidding war. A lot of people loose everything this way)
4 - Have an outlet to get rid of what you buy. (No matter how good the deal is if you don't have a buyer it is dead inventory)
5 - What sells in your area and what doesn't (scroll through craigslist and look at several flea markets)
6 - have a method to move it (start with a rental truck but make sure it is in the bid)

I see so many new faces everyday and only the same 5-10 people at all of the auctions.  The vetrans stick together and have deals between us of who buys what.  We are a tight group and regardless what anyone says we take in very few newbies and everyone has to prove themselves before they are taken seriously.

If you are serious then it will not be an easy road but in the end it will be worth it if you stick with it.  Happy Hunting.