I have taken a number of classes through a local college and I've loved them! I have learned a lot, and more importantly, I found the peer interaction very challenging and inspiring. Maybe I lack some of the internal motivation that others have, I don't know. Whatever the case, it has helped my photography greatly. I find that the process of getting assignments and then seeing what the other students come up with is eye-opening and has helped a lot.
There may be other avenues for this, like
www.photofriday.com, but it's hard to get the same level of critique. Far too many people would rather damn you with faint praise than be honest and help you learn, even if it risks hurting your feelings. If you can find some venue for this, even a mentor or group of friends, you'll get most of the benefits of a classroom.
As for worth the money...? I'm not selling any pictures and do this just for my own enjoyment, so "worth" becomes a very subjective thing. I make a lot more money than I can spend, so a few hundred for something I love isn't even a consideration. If you know how much every frame of film costs you and you know how many rolls you can shoot before you have to start rationing your food, then reading some books in your library and visiting some local galleries may be a better investment than a class.
Most classes will demand (rightly so) that you have a camera which can be fully manual. I don't think your Powershot will qualify, which means you'll have to use your film camera. And if you say you don't have enough money to experiment with film, remember that in addition to the course fee, you will be expected to shoot several rolls of film every week. You will also be expected to use professional quality film, and get it developed at a professional lab, which will end up costing you more than WalMart or the other 1 Hour Finishing places. All of this may help you be more efficient in the future and figure out why some of your digital images aren't up to scratch, but if you're worried about the amount of film you're using currently, a class will just make this worse in the short term.
Mamabear: you can definately teach yourself, but you need to be disciplined. Just shooting a lot of pictures isn't enough to learn or to grow. You will need to learn what makes a good photo, and what makes a bad photo, what are the rules and when you can break them. With a basic grounding, and with discipline, practice can help. But I spent years taking "holiday snaps" without ever improving. I guess I'm saying that the quality of practice matters far more than the volume.