BMW is a bad example, you could print those initials on bog roll and flog it for 20 quid a sheet. Labour might be 150 quid an hour in one of their garages, but the mechanics are on a tenth of that, hence why I see it as pretty shoddy. What I mean to say is, can you justify with clear conscience charging a tenner for a few minutes work, with bugger all wear on the tools, not a lot to go wrong and no consumable items bar the grease?