to everyone who uses USPS with insurance - have you ever tried to make a claim on that insurance? I have heard it is quite difficult. Especially if you don't have any kind of an invoice that shows a price someone paid, like if it is a gift. Sure, they will be happy to take your money to insure it for $500, without telling you that you may not be able to collect if something goes wrong.
I have had 2 claims with UPS insurance - piece of cake both times. Under $100 they don't even send anyone out to see the item or want you to send it to them. They just pay the claim, after seeing the invoice.