Yeah, I'd say $18 is on the cheap side
It's more of a relaxation/meditation thing
So you really don't 'get anything out of it' (well as grateful said...it cures cancer too, but the undetectable and non-fatal kind

)
Typically you are laying down with an eye pillow for 45 mins
it's a live thing, don't think it would be the same if you just put on a cd
they use things Tibetan sound bowls/gongs and other devices that produce vibrations you feel
For me, it's more enjoyable with a few tokes first
But you definitely need to be comfortable lying on your back with your eyes closed for 45 mins with a group of people
The new thing is sound baths, floating in a pool (you are on a inflatable mattress )