A little late to the game on this thread - I just now saw it.
I've been flying professionally for about 17 years, and am currently an FO at a major airline. It's been a good career for me, but you've got to approach it from a desire to fly, and understand that the lifestyle isn't necessarily for everyone. The industry is cyclical with the economy, and although things are on an upswing at the moment, the music can stop at any time. The career path is strewn with pilots that got into this gig thinking of the $$$ of major airline pay, but because of timing or just poor luck ended up stuck in lower paying jobs through no fault of their own. If you enjoy the flying and are cool with the lifestyle, then getting 'stuck' somewhere that's not a major airline isn't as big a deal, as there are tons of other flying gigs out there that are pretty cool in their own right. Just go into it with your eyes open.
As others have mentioned, it won't be cheap to get all your ratings, and then you have to figure out a way to get to 1500 hours to be employable at a regional airline. Whether it's flight instructing, towing banners, or whatever else, you're not going to be making much money for the couple of years it'll take to get that flight time. Fortunately regional pay has really come up in the last few years because of the pilot shortage - with hiring bonuses $60K+ isn't unreasonable to start, and with upgrade to Captain in a year or two the pay jumps into the low six figures.
The money gets pretty good once you get out of the regional level. Even places like Frontier, Spirit or JetBlue have gotten decent contracts in the last few years, and while they're not quite at the level of the Big 3, they're pretty close. Just remember that if you're struggling with the lifestyle - being on the road for days at a time, dragging your bags through throngs of people in the terminal, working weekends and holidays when you're junior, hotels rooms and hotel bars, etc....the money doesn't make any of it better. So like I said, you've got to be cool with the lifestyle for any of it to work.