It makes sense to insure anything that would be costly enough to really make a dent if something happens. I haven't always done so, but since you brought this thread up, I will probably do so from now on. Thanks for the heads up.
Why would you risk it?
Given what happened to the UPS Cargo plane that crash landed, caught on fire and had all of its cargo contents destroyed recently. I hope that you reconsider if any of you have things shipped not fully insured/declared (for customs) just to save a few bucks or to? I feel for those who had things on that plane and more so for those who did not have their contents fully insured.