i'm no longer cheffing, but i put about 20 years in the industry, starting out washing dishes at 16 and eventually working my way up to sous chef and executive chef positions.
what you get from a good culinary school is a fairly well-rounded basic
knowledge of all the important aspects of the culinary field. i'd stress the basic part, as you will still not be an expert at anything. better programs will also provide you with job opportunities and connections.
the difference between going to a culinary school and working your way up the ranks is that to build up the same general all-around experience and connections will take many more years. in the meantime, though, you will be becoming proficient at some aspects.
of all the people i ever hired, i don't think i ever based a decision on whether or not someone had graduated from a cooking. amount of experience and checking up on recommendations is what mattered. and the fact that some had a degree from a culinary program certainly never saved someone who just wasn't working out from getting fired.
you may (or may not) be able to get a job as a line cook directly out of culinary school. it would probably take several years longer to work your way up to that position otherwise. but not necessarily, if you have a strong work ethic, are a quick study, and make yourself available when the chef is in a pinch because someone is sick or doesn't show up.
you will not be making what many might consider "real" money as a line chef. not until you can land a position at a really fine establishment. and your pay will not be based on having a degree or not, but based on the position you are hired for and your experience. you don't really make decent money until you become a sous chef or executive chef, at which point you will be on salary and pretty much kissing your personal life good-bye due to the hours.
it may seem that i'm coming across with a somewhat negative attitude, but that's not what i want to convey. if you enoy cooking, it's definitely rewarding. 95% of it is simply a job, like any other. but you do get to be creative; more and more so as you gain in experience. and there's a lot of comeraderie. but the bottom line is that you have to sell a product. and the restaurant business is and always has been cut-throat.
in the short-term, what you need to decide is if it's worth several 10's of thousands of dollars to distill say 5 or 10 years of exerience into 2 years or not. and remember that in repaying a loan, you are actually repaying about half again what you borrowed. i'd ask mark what he thinks about this in today's market.
as a middle way, another option would be to start workng your way up in a good establishment and taking occasional courses at a junior college or somewhere to expand your horizons, especially on basics like learning how to make a good brown sauce, etc. in this respect, a culinary school is the way to go, as most average restaurants use a lot of commercial products, and it can be hard to pick up these skills on your own until you can get jobs in a better class establishment. that said, there are a lot of chefs who are willing to take promising aspirants under the wing, so to speak. but it's kind of the luck of the draw on this point.
well, i could probably babble on for years, but i hope some of the perhaps contrary infomation/opinions help you.