Hi, I'm actually a physio, as is my husband, and he has postgrad qualifications in back/neck/spinal pain.

There are a few different schools of thought with regard to back pain and tons of research around on it, which makes it very hard for the average person to know what the best treatment is and how to get it. What we know doesn't work:
massage (feels nice but doesn't fix the problem)
ultrasound
bed rest

We both work using the McKenzie method, which is based on the patients responses to various movements and repeated movements. Basically it comes down to you doing certain exercises (very specific to each case) which will reduce the pain and increase your ability to move. The beauty of this approach is several fold. There's little hands on, so you don't get pushed and prodded into pain. You learn how to treat the pain yourself so you don't have to go as often. The exercises should give you immediate pain reduction. I did a comparison study at a place I used to work on how many treatments patients needed before they were discharged, and it showed that patients treated with McKenzie approach needed about half the treatment sessions to get better compared to those receiving other treatment. Oh, and even though someone might have had the problem for years, it can still respond well to treatment, saw it with a grand rounds patient in March who'd had pain for 10 yrs and after one session with the top bloke had no pain at all!

The cost of physio is very dependent on where you live too, some are expensive, some aren't. You can find a McKenzie physio by googling for their directory in Australia (or you can pm me as i have a hard copy) or you can find tons of physios by looking in the Australian Physiotherapy Association's 'find a physio' directory.