This is one of the problems I've had in the past with my Fleabay sales ........ DSRs marked down because the buyers didn't like my shipping costs....... Even though I make it clear to buyers to ask for a shipping quote to avoid any surprises. Of course, there's always one that just bids away and pulls a face when they win it and get the invoice, but that's their lookout I'm afraid.
International Tracked & Signed, or International Tracked (formerly 'Airsure') services, for instance, can see a 350g package (eg: a cased razor and some blades), with a declared value of £100 and heading for the US, cost roughly £15 ($21.38) or thereabouts. These services are the only ones that Royal Mail provide at that price level that leave you covered under Ebay and Paypal protection policies. That doesn't mean a thing if it goes missing, really ........ You still have to reimburse your buyer and take it up with the courier; but it does make it a lot less likely that a dishonest receiver notices that their delivery is not tracked and insured and decides to pull a fast one on you.
I can state, however ...... That I've never had so much as a single item go missing yet. I've had a few squeaky bum moments waiting for them to arrive beyond expected delivery dates ....... a parcel containing 1.5kg of vintage razors taking two weeks longer to turn up in India come to mind ........ but, so far .... a 100% record.
There are still a lot of countries on my exclusion lists though ............