Yes but buy ten ticket in one transaction and you have to pay ten booking fees. How unfair is that?
For music tickets, if you are buying from a ticket agent (which, essentially, is anyone other than the venue direct), face price is the price
they pay, so wat you're saying here is essentially equivalent to suggesting that if you buy ten items in a shop you should pay retail for one of them and get the other nine at wholesale price.
Except in practice it's usually worse than this because of the "rebate": an additional fee paid by the agent to the promoter on each sold ticket which is passed onto the venue. So, when you buy a £45 face value ticket from an official legitimate outlet such as See or Ticketmaster, they probably paid about £46.50 for it.
[ edit: why isn't ticketmaster caught by the swear filter? ticket*ast** ]