Costing is much more than a simple "what do the parts cost us, how much do we pay the technician?". Factor in:
- Cost (to Canon) for warranty on the repair.
- Insurance (of your product) while on their premises.
- Return shipping charges.
- Packaging materials for return.
- Salary of person packing your gear for return.
- Overheads and general cost of maintaining a US repair facility (light, heat, premises insurance, telephone, stationary, etc).
- Local taxes for providing the facility.
- Training costs for technicians.
- Salary for technicians while training hence not earning money for the company.
- Employee insurance costs.
- Public liability insurance.
- Cost of holding the parts in stock at all.
- Cost of diagnostic machinery (whether or not it is used on your particular job it has to be available).
- Even the costs of booking the equipment into their facility / booking it out for return / raising an invoice / bank charges for processing your payment.
- Et cetera, et cetera, et cetera.
- Then there is the small matter of profit - no-one stays in business for very long if they do jobs at cost.
It always hurts when we get a bill for repairs. Always. If you're professional, it should be covered by your equipment insurance. If amateur,
possibly by your household all-risks insurance??
I too don't feel that you've been ripped off at all. Granted that others may get a more expensive repair done with more parts replaced for the same flat-rate charge. So may you one day
(though I sincerely hope it won't be necessary). Conversely, someone may pay the same amount for simply having the zoom reflector adjusted with no parts used at all. It's the price we pay for having the facility for in-country repair - imagine what it'd be if everything had to go back to Japan for repair and
imagine how long you'd be without your gear.