Its got nothing to do with the money (My local one is £15) - but it is the risk that they don't know enough about the specifics of old classic cars anymore. Reving the nuts off my Spitfire is not something I want to have done - some oik driving my spit is not something I really want to happen either - they are all a bit quirky how they start and drive and if anyone is going to break it, I would rather it be me.