I'm glad you are thinking about your preparations now.
There are so many things to consider while preparing for something like this, and money is just one of them. If you've seen an ad about making money teaching ESL, yaughts, sailboats, villas overlooking the Med, forget it. Nobody is getting rich. If you have school loans to repay, you'll barely make a dent.
If you are looking for something challenging, something that will help you develop teaching skills for your career, business skills, diplomacy skills, so many other skills you never knew existed till you got them, then jump in with both feet! All of us are still developing those skills--or should be--and many of us are on our second profession.
As you read through the messages posted in these forums, look for commonalities. Read between the lines. Try to recognize what seems OK, and what doesn't feel right.
Good luck.