This occurred at a club I was with a few years ago. I spoke to a local customs man who assured me they did not charge anyone. It turned out it was a fee imposed by the airfield for faxing the GAR. The customs man told me that in law it is the responsibility of the pilot to report, but that if an airfield wanted to make it part of their conditions of use that was up to them....... I moved to another airfield and send the GAR myself !