I feel that one thing that if frequently overlooked is that anytime you chuck a customers shaft in your lathe and starting cutting you are taking on a certain amount of liability. I have come close to making stupid mistakes rushing around at tournaments trying to talk to customers while working. I know of other repairmen that have damaged shafts either by being careless or bad luck.We also have cost in equipment, consumables such as sandpaper - glue - blades - etc... , time to setup and be present for the day. $40 for labor only does seem steep. I charge about half that.