Good thing is it is doubtful a postal worker will risk losing his job over 1 package. When my dad died expectedly in 2006 I made his brother a memory quilt incluing pictures of him running a marathon, pictures of his cats and his orchids. When I shipped it fex ex ground (I find it cheaper and more reliable then usps) they require you to list the contents of the box. Even though it only cost me around $100 I paid to insure it for $1,000.
A word of caution - I found out a few months later from a client thats in management at fed ex as a quilt I shipped was lost. They only pay actual value or replacement value. If you pay $100 for something and insure ot for $1000 they will not pay you $1000 unless it costs that to replace. I had to purchase new fabric and forward the receipt and a list of my work billed at a "reasonable rate". They ended up paying me $463 of which $109 was fabric replacement.