I've had this happen to me as well and it's not very nice, especially when everything is hand made with love and the best materials.
I've had folks email me saying my shipping is ridiculous. Shipping costs what it costs, you have no control over how much a mail service charges. Personally I'll never agree to send an item uninsured or untracked as at the end of the day it is protection for both you and your buyer.
There are plenty of lovely customers out there who will be happy to pay the prices you charge. It's a shame that one person has the upset you.
As dragonfly said, you learn to spot these people a mile off after a time
Love pkw xxx