I think it's fair, they're a business not a charity.
so you would happily pay more than double mark up on something just because its delivered by a bright orange van? bollocks
if it was an independent garage coming out to repair the car, i'd be happy to pay £330 for parts and labour, expensive? , a bit but circumstances dictate that you need to pay that to get going.
the fact is they sold him an alternator that was way over priced, so that they can recoup some of the labour, which imo is wrong as he has already paid for the labour through his membership