Well, the website says 450 Baht for a 60 minute massage, but I seem to recall paying a bit more than that - think I had a 90 minute massage plus brekkie and some herbal **** chucked in for 700 or so perhaps? I was there with a Korean girl so perhaps I got given the Japanese/Korean price details complete with 50% mark-up

It may have been service charge and tax.... Some places add those on, hotels especially.
Worth checking the total cost before starting treatments because it is disappointing to find a different price at the end.