I recently thought about doing this.
Each treatment is anywhere from $160 to $200 (this is for a Brazilian treatment, prices vary for different body parts), then you have to buy the numbing cream that can be from $35 to $50 a tube. (Some have been known to do it *without* the cream... and, well, I used the cream and I'm telling you... there is no way in HECK I'd do it without. Ouch.)
"They" say you'll need anywhere from 4 to 8 or more treatments to get rid of all the hair - appointments at 6 to 8-week spacings - because of the growth cycle of the hair. The treatments can only kill the hair follicle in the first stage of growth, and they all grow at different times, hence the need to go back.
I did one treatment, and decided not to continue.
HTH!
Anne