i've been learning from books. there are a few out that you can browse or pick up from chapters that are pretty good, some of the more thorough ones are a bit pricey but much less then $200! there are also little pocket versions that give you just the basics for much less.
the other thing is if you buy a sewing machine from sears, not sure about other places, they used to give you free sewing classes that some woman ran. unfortunately i missed out on mine, but found books and a little practice very helpful.

Have you checked the Continuing Education flyers? (put on by the VSB) I think they often have sewing lessons, though you might have to travel outside of the downtown area.

Do you already have your own sewing machine? If you do, you may want to just buy some scrap fabric, and practice some of the basics. I would suggest sewing some basic pieces before throwing yourself into costume making, which is probably more intricate and involving more difficult fabrics.

If you're hoping to sew dance costumes, a serger may also be helpful....

www.continuinged.ca/courseinfo.htm

I know that those classes have already started....but it will give you an idea of what they offer. They have beginner's classes for about $130. (scroll down past the Fashion Design classes...it's closer to the bottom)

Hope you find something!