There seems to be a huge variation across the country on R44 rates, whereas for the R22 the differences are much less. When I was looking everywhere for good R22 SFH rates I could not find much difference, and I also tried for ages for a share without success. I did manage to get a block rate for the whole of one winter by paying up front for a school's "spare" one, but the result was that I got so used to having it around that I wound up buying my own.