UPS includes $100 in insurance on any ground package and the US Postal Service includes insurance on the first $50 for Priority Mail packages.
If you decline insurance when you check-out, you can file a claim with either UPS or the Postal Service. UPS does a nice job of paying for their losses, but good luck with the Post Office!
If you buy insurance from us when you place your order, we will re-ship the missing parts of your order and we will file all of the paperwork related to a claim for lost or damaged merchandise. The insurance company we use (UPIC) always pays on their claims.