ZT/Kershaw send out most parts for free, an excellent service that puts them at the top of the heap, things like fancy pivots and milled clips need to be paid for, which is very fair.
Benchmade send out many parts for free, though some internal parts are considered on a case by case basis but may require the knife to be sent in, still a very good service.
CRK will send out many parts for a relatively small charge but some parts require the knife to go back to base, good service but the requirement of ~$70 return postage is not much fun for international warranty work.
EKA really work with their customers and have sent out all parts for free but not sure what their official policy is.
As an international I'd appreciate easy access to spare parts but won't offer any real detailed opinion as I know it will make little difference in Spydercos decision making. Honestly, I think it's better to just ask Spyderco, where do you want to be on this issue? Where do you position yourself in the above or the rest of the worlds knife market? Doing some market research and seeing what is commonly accepted practices so that you can better position yourself for the future. Importantly, what would you like to have available to you as a customer, sending a product in with expensive back and forth postage, or purchasing a relatively cheap part to fix your issue? make sure you include the opinions of the guy's working the floor, the average blue collar worker, not just the financial gurus
