how can I insure a shipment for more than $10,000

I am not sure of your situation. But I have my dealer do everything, so I am never in a position of shipping anything like that. 

what is a dealer? That is only half joking.There are no high end dealers with 3-4 hours of me. Even if there were, I can't afford to buy what I want working with a dealer, so like most of us, wheel and deal on sites like this. 

and I'm talking about selling a used item I have, No dealer is going to help me do that.

I took it to Fedex. I don't know what the limit is , but they did go $19K. It looks like the 3rd party sites that offer discounted shipping have their own limits. The ones I am used to using cap it at $10K. 

all good... thanks

Registered mail through the US post office is your best bet.  You can insure any shipment for up to $50,000.

It’s cheaper than buying insurance from FedEx or UPS.  And it’s very safe—your box will be locked up during the shipment process.

However it can be very slow.  It could take anywhere from 7 to 18 days to be delivered from my experience.

You also have to seal every edge with brown shipping tape.  You can find the tape on Amazon.  It’s the type you have to wet down with water to stick.

I’ve shipped almost 100 packages using registered mail and every one was delivered.

I have found using the Mail to insure, has been $$$$.  If you can put the equipment on a palette, most trucking companies have very low insurance costs.  I suppose the reason is they rarely have to pay a claim?  A pair of amps I shipped recently, insured for $40,000, cost me $65 for the insurance.  Cheers.