You buy insurance with the hope that you won't need it, but you sure are glad that you bought it if you do need it. If you need it and you don't have it, then you're just plain SOL.
Only you can decide if it's worth it to you. Most people here have commented that they're willing to risk up to $100 w/o insurance. My limit is closer to $25. I've had 3 losses of things that I've shippped (2 were insured) and one loss of something shipped to me. I have shipped and received MANY packages and the % of success has been pretty good. I EXPECT success, but I buy insurance for the failures.
Tracking (if we're talking about USPS) is a ripoff and a complete waste of money. It does NOTHING. It means NOTHING. There is no recourse. Either insure it or not, but don't throw your 55¢ away on Delivery Confirmation. It's like buying credit insurance on your credit card, except credit insurance is real. If you die, it'll pay. D/C does nothing. If you insist on spending it, send it me - at least I'll say "thank you."