We had 12 done a couple of weeks ago by McTimony lady. Cost should have been £35 but due to numbers we had her for £30. YO paid £25 for each of hers to be done (understand its called Perks of the Job)
I think the bloke who comes up to our yard is £50 a session.
However, I recently successfully treated Chloe myself, with some virtual help from my human physio, so thankfully I haven't needed him to look at either horse yet
We have a chiropractor who charges £45 per horse (unless there are no probs - cheaper, lots of probs -more expensive) plus £10 callout which is split between whoever has it done.
I have just had my chiro/massager/physio out and it was £37 as I was on my own, but usually there are others and it is around £34, depends on how many she treats.
I don't have a physio, I prefer to have an Osteopath.
Costs me £40 including travelling. If she feels the horse requires no treatment then the charge is only £20 to cover assessment of the horse and travelling.