Why ticket the event yourself, when you can get a ticketing company who already has the resources to do it Cheaper? The cost is hardly in them printing out a ticket for you, so I hardly see how thats relevant. Its not you paying $5 to use your own printer at all, there is more behind it than them sending an email and you printing a ticket is there not?
When you see a football match, you are purchasing 2 services, the football, and the ticketing. Again, if they simply incorporated the fee into the price of the ticket, you wouldn't be complaining. Could you imagine the money they'd miss out on if they charged a flat rate from people doing mass bookings to avoid individual fees?
Effectively, what you are charged by ticketek, is actually what the nix are getting charged for using their service. If ticketek did it for free, the nix would simply charge $5 more because that's obviously the price you're willing to pay.