shipping heavy amps - Canada to US?

UPS is out of the question. They wanted $146 to ship a passive preamp to England that USPS shipped for $28. I dealt with this problem recently myself as I was negotiating the purchase of a Musical Fidelity M3 from a seller in BC. Canada Post was the cheapest at that time. Why would he be charged for transporting his own property? Admittedly, I know nothing of new security measures since 9/11 but surly they were not intended to apply to personal electronics. Unless the amps are large enough to be considered a weapon. Don't laugh, I once had a custom agent at Kennedy airport spend about a half hour examining the Stax arm I had ordered from Japan. He didn't know what it was and this made it suspicious.

Canada post sucks! period.
Fedex and ups can ship but it's expensive.
If they can drive across the border, that's the best way. It's up to them if they want to declare the amps at customs. If they are smart, they will declare them. They will need a bill of sale from you to avoid paying customs on the full retail price. They could get away with a reasonably low sale price and pay the customs on that. If they go too low, customs will know (they'll google it).
The buyer should be honest that shipping was too expensive and the amps weren't worth that much.
Just keep in mind that Canadian customs are greedy...

I think Canada Post has a limit of 30kg. UPS ground does not include brokerage fees but UPS air does. UPS also has a "dimensional weight" that can double the cost.