I go for a 2 hour massage here at N16.42.830 E098.33.702.
250 Baht for the 2 hours and it wasnt bad either
N16.71224 E098.55781, right next door to the Vietnamese restaurant almost opposite Casa Mia
Wan is the masseuse that was recommended to me by friends and a very good massage too.
Definitely the best massage I have had in Mae Sot