I may not sell on eBay but I do run my own business and ship products all over the U.S. using primarily UPS.

If you purchase an item that costs less than $100.00 and the seller is shipping UPS Ground and wants additional money for insurance then they are ripping you off! UPS covers ground shipments (at least to the continental U.S.) automatically for up to $100.00. From the UPS website:

UPS automatically protects every shipment against loss or damage up to a value of US$100.00. With Declared Value, you can request protection up to US$50,000.00 per package.

Of course there is an additional charge for insurance over $100.00.