I do hate to admit it, but yoga can be incredibly expensive. When I first began the hobby, I was shocked to see yoga mats selling for $70 and one hour classes for $40. Being the cheap skate that I am, I wasn't prepared to chuck my money around if there were cheaper options. Thankfully, my persistence in researching proved to me that there was.
Don't bother with expensive equipment
Firstly, don't bother buying equipment so expensive that you might have to sell your house for it. It became clear to me quite quickly that sports stores were far too overpriced.
Kmart seemed to have everything necessary for low prices. You can purchase a yoga mat for $12, drinks bottles for $5, small towels for $8, and exercise clothing starting from $5. They might not be the absolute best quality you can find, but they do still do the job just as well.
Yoga doesn't have to be done inside a sweaty room with a bunch of other people. You can do it in your own backyard, or living room, or wherever you please. Just log in to Youtube, and find your favourite yoga enthusiast blogger.
Personally, I have become obsessed with Yoga With Tim. He's got more than 100 videos posted to his channel that demonstrate different yoga sequences. They range from 10 minutes to over an hour, and the title explains what they are specifically designed for. For example, the '20 minute Yoga for Neck and Shoulder Pain' video is obviously going to have poses designed for people who need to strengthen their neck and shoulders.
If you're in Adelaide, then there are some places you can head to for cheap classes. Something that I found reasonably inexpensive was Bikram Yoga. They currently have a deal going for a 10 day pass that only costs $25. If you do end up going every day, then that's only $2.50 per session.
The Local Fitness website also appears to have a range of different deals for yoga classes in Adelaide. They advertise discount vouchers for a number of companies that teach yoga, such as Step Into Life and Goodlife Health Clubs.