I love when this topic comes up.
I played serious money pool for years. (about 17 of them) 9-ball, Chicago, and Straight pool were my specialties. Also some One Pocket. If it had not been for a "job" and a "life" I would have gone pro. Maybe I should have. I can turn on ESPN now and see all the people I used to clinic for a few grand a night! Now, I'm a draftsman for a lighting company, and they are competing in $50,000 tourneys. Go figure!
I recently tried to take it up again. Made a few dollars, but it would definately take alot to get my game back. I could do it, and if I ever lose my job it's an option, but it will take a long time.
For those that are serious about playing...stick with it! It's a great game, and if your good enough, rich can come pretty easily.