Last week I paid just under £120 to have fitter out to re-fit WOW saddle, bill included cost of new head plate.
I can’t remember what charge was for measuring for a new WOW but seem to think it was included in cost of saddle once ordered, could be wrong! Sorry not much help. I guess best thing is to contact fitter local to you and ask.
I think I paid £60 in 2012. The man came out, made up what he thought would fit, it did not. He changed it somewhat, he said it now was a good fit. The horse disagreed. Man went away again and I was £60 lighter!!!