I price shipping at a level to cover postage and materials, not to build extra profit into pricing. I ship USPS, first class, and use CD mailers, a light cardboard mailer, to protect stamps during transit. Larger items packed with similar care. Shipping of more expensive items will require additional fees for insurance, to protect both buyer and seller from loss. FWIW, for shipping to some countries, such as Russia, I may require additional fee to cover proof of mailing so I have evidence for PayPal if claim of non-receipt is filed by buyer.