I need shipping advice

I have a very heavy item to ship to CA. The item is only selling for $150.00. The item weighs in at about 100Lbs packed. UPS is the least expensive shipper. From the east it will cost about $80.00 to ship COD per the buyers request. We have talked and I have good references on him. The item is crated well enough to survive, I hope. The problem is how can I insure this package to protect me from loss of the item plus shipping? Can I insure for more than a COD amount on an item? I'm guessing that I would need to cover the cost of the item plus shipping both ways. That's $310 of insurance on a $230.00 COD. Or is the easiest way around this to just insist on prepayment and insure to cover my butt? Or does UPS pay for the return?