Hello WIlliam,
I am new here too. I know what you mean about the cost of classes/teachers. There are a lot of good books videos and DVDs out there.
I like to go to classes when I can afford it, it is helpfull to have a teacher to help you get the correct posture, although an alternative is to get a video or DVD and work with a friend who is also of like mind. My son is a brilliant observer and has a general interest in martial arts will often sit with the book or video I use and correct moves and positions.
Sometimes it is nice to get together with friends and compare notes.
Do you work? Sometimes instructors will come into the workplace if there are enough students and offer cheaper classes as they don't have to pay for hall hire! Find out how your firm stands on this too.
Good luck.